The your heat exchanger is cracked so your furnace must be replaced scam

[@michaelshevchenko854]

I'm a college student doing the HVAC pre apprenticeship course. My parents believed the HVAC technician, but I figured out we were being scammed. My professor made it clear that a cracked heat exchanger needs to be replaced due to the danger of carbon monoxide poising. I don't know how to fix the furnace on my own, but I had more knowledge than your average person. The fact I saved my parents from spending thousands of dollars that we don't have feels like an accomplishment.

[@danieljolson5884]

I have a problem with my flue gas pressure switch making up so my burners can ignite. The flue gas blower had failed. I replaced it with a new one. The switch itself is new but when I fired up the furnace it won’t ignite the switch won’t close. I’ve used my fluke meter to verify this. I can pull out the flue pipe to get it to ignite. I also placed a vacuum cleaning on the flue exhaust outside the home and verified very good suction at the furnace. Please can someone help with advice which direction to go THANK YOU!

[@scvle00]

@@danieljolson5884does the inducer/flue motor start ? if it doesn’t, check if the rollout switches are popped. if it does, make sure it pulls enough vacuum to close the pressure switches. test the switches again by gently sucking the tubing connected to it. should hear a quiet clicking

[@scvle00]

@@danieljolson5884also , check resistance (ohms) on the switch. should be OL normally. then while gently sucking the tubing connected to it, check resistance and it should give a reading. if not switch is bad

[@bertellijustin6376]

Check your glue pipe for a birds nest. Can’t tell you how often I’ve had pressure switches that wouldn’t close because of something so simple. If your inducer is good and your switches are actually good and not getting stuck, it’s likely an air flow issue.

[@OGXX-bs5bc]

Problem is sometimes the heat exchanger is more expensive then its worth. Depends on what you are working on.

[@thisisme2246]

As a 32 year veteran of the field, i have always asserted that any mechanic worth listening to will always volunteer to show you where the problem is, and can explain in common language, what has happened and what is the best course of action.

[@erkl8823]

I'm praying I can find a *good* , *honest* , fella like that. The guys that came by today were very quiet, didn't say much about anything. I had them here to replace the thermocouple on a 1975 (not a typo) Carrier, & while they had it open I asked if they would vacuum out the building up beneath the burners, they did, & then they stood & watched it cycle a couple times & said the flames had a bit of odd movement as it cycled on, which they said indicated a possible hole & therefore could require complete replacement. Then I start reading about how that's how they drum-up work when it's slow, which it's obviously not rn (early January), & I don't think I'm in much of a position to question it, since my heater is almost 50yrs old... Anyway, I'ma definitely get a 2nd opinion since I've read that's a *must* , but ultimately I know the ol' thing's just not long for this world.

[@TheDarrlelennis]

30 years in and I try 2 always explain and show the problem

[@nadine91]

Have a 1969 day and night furnance. It works great. The gas company comes out each year and looks it over, cleans the burners, and looks for gas leaks and so on. Each year I get a different person. The younger ones all say to replace it. The older ones (over 40) marvel at how simple and clean the unit is and tell me the new ones are "junk." They all say their main concern is the firebox, and making sure there are no cracks, which I gather is the heat exchanger? My gas bill in winter (so cal beach area) runs about $90 a month in winter. Otherwise its about $35 a month . My neighbor s newer furnaces run them around twice as much. Anyway your videos are very informative. Appreciate you taking the time and making them.

[@TheFizzBand1]

Found this after getting this exact same story from a local hvac service. The guy seemed nice and very knowledgeable. Spent about 3 minutes then said that the little button had popped up on a sensor for the heat exchanger on my roughly 30 year old home heater system and that I needed an entirely new heater system inside and out. After watching your extremely informative and helpful video, I'm most definitely gonna dig in and do some recon of the system myself... thanks so very much and good luck with your channel. I'll follow as well!!

[@brandonandresen3744]

if its 30 Y/O and the heat exchanger has a crack it would be stupid to dump any money into it...

[@Mkjaffar]

Appreciate your video, you saved us a headache. a technician came out with the same exact situation you described. Scared my wife while I was at work into thinking we have 100ppm of CO detected in his report. I got a second opinion, who stated this was all false and tested the CO levels with no detection.

[@bobbyjayyda1]

Majed J if they haven’t done a combustion analyst, or pulled out the burners, blower then it’s pure speculation which is usually them trying to sell you a furnace.

[@flamaest]

I used to live in a condominium location where about every 5 to 10 years, they would slap notices on dozens of doors stating that they detected dozens of heat exchanger cracks and the only way to fix the problem was to completely rip out and replace the whole system. your video helps tremendously. I was convinced that this was a scam, no way that all of the systems would have failed so close together like this having yearly inspections of all of this equipment as a normal precaution. it turned out that the contract for the maintenance of all of these HVAC systems comes up every 5 years and the new companies that maintain the systems want to make a quick buck and force tons of tenants to spend thousands of dollars to pay for new HVAC systems.

[@grayfurnaceman]

Sounds pretty ugly to me. GFM

[@dwaynedickerson]

I own small HVAC company and I just wanted to thank you for producing this video!!! It is very informative and correct in every issue that you talked about… There is a NEED for more videos like this one to be on KZbin, so the public can actually be able too do a search and look up a problem, the I’ve found with there HVAC system, so the service person’s diagnosis’s can be validated in the customer’s eyes.

[@grayfurnaceman]

Thanks for the support. GFM

[@dwaynedickerson]

@@grayfurnaceman You are welcome!!

[@bryanslayter4053]

You can also do the static pressure test. With the gas turned off and the blower on, hold a burning match in front of each burner where it normally projects its flame into the heat exchanger. Use long tongs or a piece of wire to get the match directly in front of the burners. If the flame of the match becomes distorted or blown out by air coming back, this probably indicates a cracked heat exchanger.

[@andrewrossnagel9433]

This!!! So many people are gonna pay a lot more for labor when probably piss off the service tech when they say he's being dishonest lol. He's gonna take it all apart to show a leak that obviously needs to be addressed. I guess it needs to be done anyway if you are simply replacing the heat exchanger but most people nowadays rather replace the entire unit to save on bills and there's usually a rebate involved on new units

[@markmarcantonio5808]

So do I just just turn off the gas valve and turn on the furnace and just the blower will come on or do I have to jump something? Then I understand - Hold the match- watch it dance ?

[@mrofnocnon]

@@markmarcantonio5808Nope no jumping anything .

[@themonkeydrunken]

Yes! I use one of those long-necked grill lighters with a flexible neck to get a flame in the orifice. If it dances side-to-side while the blower is on, that tube has a leak.

[@michaelerickson1518]

Just turn on the fan and check no need to turn off the gas

[@picturemetrollin2093]

I recommend having co detectors in any home with gas, oil or wood burning appliances. one near the appliance and in all bedrooms.

[@picturemetrollin2093]

@Crack Shot the building code, in my neck of the woods, requires one in every bedroom. But it also requires arc fault breakers for every bedroom, so..... I used to be on your side of the fence, but I got to thinking, and that's where things usually go off the rails, having one in every bedroom would make it a lot safer for heavy sleepers.

[@erkl8823]

I have a 50yr (almost, 1975) old gas Carrier model furnace. Does Carrier have a lifetime warranty? Cause that'd be just AWESOME. Otherwise, after 50yrs, I can probably drop my guard when they say it needs replaced? They just came by & were talking about the flames moving oddly when it kicks on, but they weren't sure, & definitely didn't run any cameras in there or say they actually saw any holes...

[@grayfurnaceman]

Carrier has a lifetime warranty on some 90+ efficient furnaces. There is no warranty on yours. The Carriers of your vintage had a habit of getting rust holes in the front of the heat exchanger. That could be causing the flame changing. I would replace it. GFM

[@andydanzig1926]

I really appreciate you making this video available. I have a ThermoPride Model OL16-25 oil furnace installed in 1993 that has been serviced annually. Every tech who comes comments on what a great furnace it is. A different service tech company, a sub to my oil company, came out a couple weeks ago to do the annual maintenance. He did a combustion analysis (something he said most companies don't do), which said showed a cracked heat exchanger and recommended replacing the furnace. He based this on changes from readings before and after the blower turned on: CO2 from 10.4% to 9.2% and Excess air from 50% to 70%. (He only gave me a printout of the after blower readings, not the before.) CO read 0 ppm, but he said that's not measuring the air in the duct entering the house. His father, the owner called me a week later, to tell me the same thing. When I questioned the CO reading, he said they could measure ambient CO by drilling a hole in the duct work, but that I would be charged another service call for that. I have a working CO detector in the central portion of the house. Isn't CO formed by incomplete combustion or in a low-oxygen environment? Why would it be present from burning oil in air with high O2? The owner of the oil company called me tonight to tell me he was reviewing the service sheets and alarmed the tech didn't turn off my furnace. He offered to send his own tech to run the combustion analysis to confirm if there really is a crack in the HEx. He really hopes there isn't and that I don't need a new furnace. He said if they find one, they're required to turn off the furnace because of the imminent health threat. When I asked if he'll measure CO in the duct, he said they're not licensed to do that. Is this "requirement" to shut off the furnace real or a ploy to sell me a furnace quickly? Because who wants to be without heat when it's cold? Also, if there was a serious problem to be concerned about, wouldn't the CO detector go off and we'd notice a sulfur smell or something? Your thoughts and advice are greatly appreciated.

[@grayfurnaceman]

First, I am concerned about the change in combustion when the fan comes on. That is an indication that the separation of the combustion gasses with the circulating air has been compromised. CO may or may not be produced but if it is cracked, that could change with more use. The issue of not being licensed for ductwork CO testing is suspect to me. You have a detector, and they are quite sensitive. In some jurisdictions, they are required to shut down the furnace if the heat exchanger has a crack. Generally, if there is leaking combustion gasses into the ductwork, there will be a smell. CO does not smell but other products of combustion that usually accompany it do. Lastly, heat exchangers are replaceable. GFM

[@andydanzig1926]

@@grayfurnaceman Mr. Gray, Thank you for your thoughtful reply. Our town building inspector confirmed that the oil co. is required to shut down the furnace if a crack is detected regardless of CO detection. At his suggestion I called the Fire Dept. which came out right away with 2 CO detectors. No CO was detected at the furnace before and after the blower was on, nor in the air in the house at the vent outlets. Rather than have my oil company rerun the combustion analysis and risk having my furnace shut down, I'd like to have heat while I get estimates for a new furnace in case I really do need one. Does this sound reasonable?

[@andydanzig1926]

@@grayfurnaceman PS. I'll also install a CO detector next to my smoke detector near the furnace.

[@grayfurnaceman]

@@andydanzig1926 I think you are ok with running it. The CO detector would be a must for me. I also would not let any grass grow under me on getting this repaired or replaced. GFM

[@andydanzig1926]

@@grayfurnaceman A quick update. I hired an independent service guy (from a reputable reference) to check out the furnace. 2 things were readily apparent: 1) the gaskets on the 3 ports that he opened were shot and had to be replace; 2) there was a lot of ash in the heat exchanger and in the flue pipe elbow connected to the furnace. He didn't expect to see so much ash less than 3 weeks after it was allegedly cleaned. He vacuumed it out and searched for cracks by shining light on one side and looking for light on the other side. No cracks were found. I was hoping he'd be able to repeat the combustion test, but he said his instrument was out for annual calibration. He thought the worn gaskets could have accounted for the other readings and assured me the furnace was fine. My next step is to contact my oil company and see if they'll own up to the sloppy work of their technician. Any advice on how to approach them? Thanks again!

[@donreinholz8121]

We had this happen to us by a furnace repair company that uses their fancy camera. We didn't do it so then he said our furnace passed. A friend told me to only use a company that has been in business for many years instead of one that ran a big add in a newspaper with a special coupon. Good advice! Great video!

[@Vinces618]

color of flame can indicate crack exchange,, not always but is good starting point if you have solid blue cone i wont worry about it

[@Denniss7420]

Seen this scam too many times. I've seen newer high efficiency units where the condensation drip tube was backed up and they were trying to sell the customer a new circuit board. Saw a 2007 Forced Air Furnace being replaced because it had a bad circuit board! Also saw an HVAC company sell customer a 450 dollar control valve (which didn't solve the problem)............................because the Customer didn't even have gas to the unit! Her house got new gas line for a tankless water heater and they left an appliance valve in the off position somewhere in the attic. When I get called for a heat exchanger and cannot find anything (either by using CO detector or physical inspection) I refer them to another HVAC company for a second opinion. Most of the newer units come with a 20 year warranty on heat exchangers.

[@grayfurnaceman]

Sad when we fail. GFM

[@dpeagles]

What about when the blower comes on and the flame immediately rolls out the front. Doesn't take long to diagnose that.

[@grayfurnaceman]

+dpeagles That's an easy one. GFM

[@TheChristianCreator]

Roll out could be from low gas pressure of restricted chimney....that’s a flag but it doesn’t mean it’s cracked.

[@siamakaghazeinali]

if the exhaust is restricted you see flame roll out all burners not one. if you see flame roll out on one burner or two or the flames arent even , the heat exchanger has cracked.Thanks

[@Deacetis1991]

Steady flame in warm up and rollout in blower almost always tells you what's up

[@scotttaylor3049]

HVAC Super Tech Hey Super Tech, what he’s referring to is if you have a perfect flame and negative pressure at the burner, meaning a good draft of the chimney, and then flame roll back only when the blower is running. That’s a no brainer definitely cracked heat exchanger.

[@billsteil8002]

If the role out which kicks off that's a sign. The heavy gas smell outside the exhaust pipe. The temperature on top of the furnace is over 260 degrees F. Different colored flames bounced outwards not blue but orange. Very simple. I am just an electrician tired of scammers with licenses who cheat honest hard-working people. The furnace guy's job is very hard but good-quality installations are hard to find. Everybody cuts corners and the total job is always not right.

[@thehvachacker]

Good video! I think you should have addressed flame roll out. If I am in front of a furnace with good burn until the blower starts then flame starts dancing and rolling out that furnace gets written up with a bad heat exchanger. At that point, you need to give the customer the option of tearing apart their furnace looking for the crack or hole. Most just want a new furnace when they see the rollout. It will be found yet might take 4+ hours to remove heat exchanger to show them. This means a $500 expense + cost of system replacement unless exchanger still warrantied. Most exchangers on resi last 15-30 years before failing. Unlike RTU that only seem to last 7-10 years.

[@kendallang4854]

I came to the comments to see who else talked about flame roll out when the blower comes on. 100% that's cracked

[@Slavelife9279]

Small cracks usually don’t cause flame roll out depending on location of crack.

[@bertellijustin6376]

Nah fam, I had this issue once just out of school. Thought cracked heat exchanger. Then got to the control board, tightened a few loose wires and the main molnex plug…..and whammy perfect blue jet flames. Looked like a slam dunk cracked heat exchanger but was actually just loose wires on the control board. Had to call my instructor and tell him about it (he’d said the same thing about “def cracked heat exchanger” in school)

[@deseremere]

Very helpful and educational video. Not many industry professionals will talk about it. Thank you

[@grayfurnaceman]

Welcome GFM

[@copkhan007]

The company i work for goes to the customers house and conducts a visual test of the heat exchanger and if a tiny crack is found they use camera to verify it. The tech then calls the sales manager to verify the tiny crack. The sales manager will then sweet talk the customer into buying a new furnace. The tech does not conduct combustion analysis and shuts the gas off to the unit. The customer panics and buys the new furnace. Both the tech and sales manger get commission on sale. I am now learning how my company scams people.

[@grayfurnaceman]

Pretty common tale anymore. GFM

[@allenclark271]

Well if there are cracks and you don't believe the tech. Then you go behind the tech and run the unit, then you just screwed yourself. To many people not trusting techs will get them killed. Yes scams happen but be careful.

[@HucksWorld]

Can you tell me when installing a furnace do you have to replace the plastic tube that run outside

[@GPSJayDog22]

@@HucksWorld Sometimes yes. If the old tube is the wrong type or schedule. ?Was the original vent installed correctly?,,, If it is the old clear type then YES! Some manufacturers use different size tube for the same BTU furnace depending on length, vertical rise, horizontal length and number of fittings such as elbows 45s, long radius or not as well as vent termination. The only real way to truly know is to read and comprehend the installation instruction. I know this is no easy answer but it is the only way to know. Jay 46 years, sales, service and installation of HVACR equipment.

[@Puda]

YEP. True story. 3 different big companies came to our place and used that exact technique. We had another guy coming to our house and checking literally everything including the CO levels. Everything was absolutely fine. Don’t fall for it people. Get multiple second opinions. Believe me, it’s not worth the headache!

[@kommoncents0000]

i was told by a HVAC company that my oil furnace heat ex-changer was cracked. I have removed some things on the furnace including an air duct so i can see in the plenum area, and most of the heat ex-changer. I have carefully placed an extension worklight with a 150w bulb in the combustion area through the inspection hole port. I then turned off all the lights in my basement and looked all around the heat ex-changer and it is pitch dark everywhere I look. There is residual soot in the combustion area and the flue, but the plenum and inside the ducts were brand new clean. When the furnace was running my CO2 detectors did not go off or give any reading that CO2 was in the house. A little hard to trust their inspection but I think they may be mis-diagnosing the problem. Any thoughts on my predicament, Thanks.

[@grayfurnaceman]

A cracked heat exchanger in an oil furnace is somewhat unusual. Not that it does not happen but in 35 years in the business I only found a handful. What was his reasoning? GFM

[@kommoncents0000]

The oil furnace is too large for the house, and he's is now saying that the burner and furnace are too old, he spent about 5-10 long minutes visually looking for cracks in the ex-changer with a boro-scope type camera. He says there may have been some expansion and contraction of the ex-changer as to why it's compromised. Then gave me an option to clean out the soot in there, and try a new burner at the cost of $3200 (burners are what 600.00 at the most + the rest in labor ) and there may still be a crack so a new (smaller furnace) was recommended. When running the flame looked fine to me, adjusting the air band was possible, the flames were not dancing around or blowing back. But before any problems were noticed heavy soot was collecting inside the exchanger and in the flue going in the chimney, all the ductwork and plenum are very clean. What was happening to the furnace was un-burned oil was blowing back on the cad cell and transformer initially and some oil was leaking out the bottom seam of the furnace body. All my burner parts are newer, motor, the parts from the motor to spin the pump, new suntec pump, new primary control. I have a gauge on the pump it is set at 100psi when furnace is working. The nozzle has the part attached to it to prevent post dripping of oil. He is recommending a smaller oil furnace sized for a 1000 sq. ft. home. Here is my video if you want to see what it was doing when it was still operational kzbin.info/www/bejne/b5eVZ3ukh5V0Y80

[@kommoncents0000]

I have called a different HVAC company and they fixed my problem, I did not have a comprimised heat exchanger and I did not need a new furnace. My electrodes were set wrong causing delayed ignition. Other issues were not enough air and too large a flame in the combustion chamber. The pump pressure set at 90 psi instead of 100 seemed to burn better. Another issue was my transformer was not sealing down enough on the body of the burner and was causing unwanted air flow making some oil splash back onto cad cell. My furnace is running very good now. All fumes disappeared after residual oil has been burned off.

[@grayfurnaceman]

@@kommoncents0000 Glad you found a good tech. Don't lose him. GFM

[@mikemalone6103]

Here's what you hAve in the end with a replaced heat exchanger. A $100 saddle on a $10 horse. A month later the blower dies, now your paying more than the replacement furnace, or the gas valve dies. It like putting a new engine in a 98 Taurus. Cars still only worth $200 when your done.

[@grayfurnaceman]

That's one opinion. GFM

[@hvac01453]

thats the one that will always come back to haunt you. Customer cusses you out, because" YOU " convinced him to spend all this money on a piece of junk and now he's stuck with the bill for a new gas valve or blower motor, venter motor... No good deed goes unpunished... They get this weird idea in their heads you place some kind of timing device to have something fail in a few weeks or months.. I actually had a customer complain, "you were just here last year" was actually two years prior...

[@grayfurnaceman]

Heard it too. GFM

[@KevinJLyons]

I wish I had this magical timer that caused relays to blow on boards and bearing to seize!

[@mvm932]

Blower motor is $400. Where are you getting the "thousands of bucks" from?

[@troydanielboy]

Any time I've had an hvac person inspecting my 45yrs old Lennox, I've stood over their shoulder so I could "see" what they're talking about. It's STILL running. From the 1970s.

[@KettleBlacktheBat]

I was also told about a cracked heat exchanger. He couldn't show us in person but he took a picture and there was the tiniest little mark next to a screw. He red tagged us and told us to either pay for a new furnace or use space heaters for the newborn babies (mind you, we live in Minnesota and this was in January. It was - 20 degrees out.) Got someone else out and he said he saw no crack or anything that indicated a problem. We have a CO detector down there that has never gone off. The original guys inspection has never even shown a CO reading. Our furnace is about 14-16 years old. We're afraid of getting another person to look at it because it's hard to tell who has an agenda to try to upscale us.

[@DEValentine]

Same scam pulled on me. They showed me grainy photos of what might have been hairline cracks. But no CO leaks. And the furnaces ran perfectly -- beautiful, steady blue flame. That was four years ago. Still running perfectly.

[@jimgill5706]

My daughter lives about 120 miles from me. Her Carrier gaspac's HX only had an 8 year warrantee. It was diagnosed as having bad inducer motor and the replacement quote was $500. I drove up to replace inducer motor and found that it was running fine but the HX tubes were rusted and had about a 1/4" wide crack along the bottom of the 3 burner tubes. The HX and gaskets cost almost $500. I didn't charge her any labor and it ran like new for 3 more years or more until she sold the house.

[@daviddeal1594]

Yep you can replace the heat exchanger...1 year warranty... later that winter the Induced draft motor fails... next summer the board fails in AC... just keep on throwing parts in... Customer should be given the information and let them make the decision ... I always give the customer the best information I can... then I let THEM make the decision... if the unit is over 20 years old I will recommend the upgrade to 90% technology....

[@grayfurnaceman]

Agreed. GFM

[@toastrecon]

While this is true conceptually, how will those incremental repairs compare in price to replacing the entire unit? I mean, even if you had three repairs at $500 each time, no way is that going to outstrip the $5k replacement cost for the entire unit Also, the extra 10% efficiency wouldn't see ROI on $1000 in extra cost where I live for ten years. Assuming (generously) that it would save $20/mo off of a $200 bill during winter (when it was used). I just find it's interesting that the voice of frugality says to maintain and repair an older car, but somehow the only thing that's ever done with HVAC is total replacement, unless it's an ignitor or flame sensor or something. Unless your system is a total dog efficiency-wise, there's no way that another 5-10% is going to make you money back, especially since most people aren't staying in their homes 10+ years, depending on their life situation.

[@cooltemp]

David Clawson David Clawson when using your math your right BUT 5k for a furnace change out ..... that’s high. Average furnace change out in Los Angeles, California is around 3200. With that being said, you replaced the warranty heat exchanger, then you have those 3 $500 repairs and your at the same price point but with an old heater. All this is obviously contingent on the age of the furnace and if it was installed properly from the start. Plug in 3200 for the furnace replacement into your equation, it will make more senses.

[@troyboy2050]

@@cooltemp Boy I need to move to California oh yeah the cost of living would kill the difference from Oklahoma prices !

[@toastrecon]

Maybe I should be brave and get a quote. I could have sworn that my friend paid a lot more than $3k. May have overpaid.

[@Gatsu1995]

I look for carbon monoxide in the return as the hot supply gives false readings, and flame wavering when the blower comes on. Then I verify with a visual inspection. Then we provide options and timelines for the client. Replaced heat exchanger if it is still available, or a new furnace. My local safety authority requires me to decommission the furnace if it is cracked until the system is repaired. Until the repairs are completed I make sure my clients have space heaters free of charge until the repairs can be completed. My clients almost never doubt me because I present them with all of the relevant information in a professional manner.

[@fjschneider]

I appreciate people like you. Thank you for sharing your knowledge.

[@grayfurnaceman]

Welcome GFM

[@JackieGreeneBeauty]

Thank you! My furnace got water in it due to high winds and rain. I dried and clean best I could and got working. 1st Got professional cleaned. Then got flame rollout and safety shut off. 2nd guy hit reset told me I need new furnace. 3rd guy checked gas pressure was ok. Still rollout and safety turn off. Checked vents, flue on roof, and finally discovered exhaust vent on top of furnace not connected! First guy must have moved furnace when pulling to clean! 4 service calls and 3 guys with 25 years experience missed this?!?! Reconnected and furnace works fine!!

[@grayfurnaceman]

Welcome GFM

[@johnshaw1670]

I just got a call from someone this weekend that was told they had a crack in the heat exchange, and the contractor turned off there furnace with the Idea they would be back on Monday to replace the furnace, and if they canceled the job they would have to pay a 25% cancellation fee. when asked if they where shown the crack they said no, but the contractor told them see the sparkles in the flame! that means you have a cracked heat exchange. All I found was a burned out hot surface igniter no cracks, no signs of cracks, no elevated O2 or CO2.

[@grayfurnaceman]

Sometimes, I just can't believe what some of these techs do. GFM

[@michaelmace924]

Unbelievable!! There's so much honest money to be made out here if you're good.

[@grayfurnaceman]

So true. GFM

[@rodneybrand8521]

John Shaw...my a.c. wasn't cooling right I called a hvac tech..he told me my compressor was going bad and for 1,800 he could fix it I told him to forget it I paid him his service call..called a Friend who had a brother who was a hvac tech..about 20 min's later he came in turned the a.c. on and you could tell right away it was blowing harder and cooler..the A coil was dirty and he cleaned it ..WOW !!! Guess the other guy was trying to make some fast cash..you have to watch some of these guys..Cheers 🍻🍻

[@mitchdenner9743]

@@grayfurnaceman and you wonder why homeowners and do-it-yourselfers are coming on KZbin and watching your videos to try and fix and diagnose their own stuff can't trust anybody nowadays

[@evelynmahoney3569]

I'm so glad you did this! I was told I had a cracked plenum and they COULD red-tag my furnace but would let me slide if i agreed to buy a new furnace from them for $4,000.00. It was about 20 years ago. My furnace was only 10 years old. I got a second opinion which involved a carbon monoxide sniffer. He said that if the plenum was cracked, there would definitely be carbon monixide registering on his meter, but there was none detected. The scam company even sent me an estimate that included pictures of soneone else's cracked plenum (supposedly mine, right?). I still have the same Furnace. I've never heard of anyone having this experience until your video. It's nice to hear if validated. Edit: Almost forgot - It was Christmastime and they offered to provide a fake receipt so I could claim it on the current year taxes if I agreed to sign a contract for them to do the work in January. Write-off a furnace repair for your main residence? I don't think so!

[@jimdesalvo8873]

Im going through this now. I have a small house and the guy told my wife 10,000$ for a new furnace

[@evelynmahoney3569]

@@jimdesalvo8873 Jim, Search KZbin for your furnace symptom. Mine was a loose ground wire, fixed in a few minutes. But the ripoff co. said beyond repair & $4k, can u imagine?! Could be something you can fix urself. If you can get a good idea what's wrong, you'll be able to know whether it repairable, or what part it needs. You can Google the part prices & labor cost, so you're not getting ripped off either way if you DO need to bring someone in.

[@mrofnocnon]

they were nothing short of criminals

[@Niazuma737]

So I have this exact situation right now, the furnace tech told me he saw the flame in the first burner bouncing around and told me it meant there was a crack, he tested it for carbon monoxide and was surprised it came back clean, any advice?

[@murkyturkey5238]

No he could be right. If the flame is moving around and not a steady flame it could be a cracked heat exchanger. Ik this is a lil late but he could be right

[@AC-io8qs]

I had a tech point out some flame rollout and a yellow flame on my '97 Lenox and said my heat exchanger was cracked when my furnace would only stay on for a few minutes.. I cleaned the blower, the coils, flame sensor, the flue, the burner assembly, oiled the induced motor, and replaced the high temperature switch and it's working flawlessly. Turns out this model always has a little bit of flame rollout on ignition due to the placement of the igniter. Reading of zero on the monoxide alarms still.

[@bdi3798]

Thanks for posting - You mention CO readings in the duct but not CO in the exhaust. A 90 year old couple I know just got jobbed for a new furnace. They showed them the combustion analyzer reading of 8ppm CO and said he was legally obligated to disable their furnace right then and there. CO in combustion gas (at thresholds up to 50,100, or even 200) is expected but homeowners don't know that.

[@grayfurnaceman]

Definitely a scammer. GFM

[@BHPaintingRefinishing]

The gas furnace in this house is really old. How hard is it to clean it out, sort of afraid that the dust build-up could be big? I do smell a little gas when I come into the room. It is bulti into the wall and vents to a bedroom and the living room, the flue goes to the chimney. No fan noted, If I get a carbon monoxide detector, if it goes off, that is proof to shut down the furnace? Sorry for so many questions, this is a rental property that I or friends have lived in for a long time.

[@grayfurnaceman]

I would be concerned if I smelled gas in the basement. You need to get someone to look at it. A CO detector is a great idea, but a thorough inspection should be done. GFM

[@ChristianApologeticsTruther]

I wish my customers could see videos like this. Sometimes I can jump through all these hoops minus the combustion check and they still call me a scammer. Watch for a rollout and dancing flame when the blower comes on, take the burners out and use an inspection camera, show them the pictures, and then they say that it’s a scam and that carbon monoxide doesn’t come into the house because of cracks. I had a “science” teacher tell me that having cracks isn’t dangerous. I calmly tried to explain to her that it’s true that not all cracks mean immediate danger but that it has the potential to be deadly. In cases like that I say I’m going to shut the furnace off until we can get a new install. I always explain to them that we can replace the heat exchanger if it’s under warranty but that if the warranty is about to expire and they put a new heat exchanger in then it’s not guaranteed to last another 20 years like they think. It’s like throwing a new motor in an old rusty car. Eventually you’ll have to replace the fuel system and shocks and struts. It doesn’t make a whole lot of sense. The part where people get angry is when I try to disable the furnace. I only do this because I’ve had more than one person who was suffering from flu like symptoms only to find out she had a hole in the heat exchanger. Make a video about red tagging furnaces.

[@andrzejhajder6405]

Nothing add nothing subtract,You said everything.

[@andrzejhajder6405]

I just shut off the unit

[@dmfb68]

You're 100% correct. Been there as well. I find it funny when we take our cars to get inspected and if it has an exhaust leak that needs to get fix but God forbid if you should make the same case when it comes to a person's furnace. It's okay/normal to be running a a 35 year old furnace knowing it has cracks but it's more important to replace a one year old cell phone because it's outdated. I've always said it ppl don't buy new hvac systems because it's a boring buy. You can't show it off and brag to your friends about it. can't wait to retire from this field.

[@RARenfield]

@@dmfb68 Last time I checked the new iPhone still doesn't cost $7,000. HVAC systems have gotten nothing but less reliable. And in the 20 years since I last bought, they've doubled in cost. If you could do something different with the new unit (like you can with your new phone/computer/camera) that argument would make some sense. But you cannot. If the inventor of Air Conditioning, old man Carrier, was resurrected today, he would know exactly how to operate and service a brand new Trane. Nothing has changed in 100 years. Just gotten crappier and more expensive. Heat exchangers used to be cast iron and they lasted 45 years. Why on earth would anyone want to replace their HVAC? The lie that it will use less energy? Ahem. B.S.

[@dmfb68]

@@RARenfield I'm sorry, I'd leave you a comment but there's a bunch of babies that work for KZbin and delete my comments because Their feelings get too hurt on how the real world works.

[@EurekaRecycler]

Hi, A friend ask me to look at his old Payne gas furnace with a spark ignitoin. When I got to it the rollout thermostat was plugged in (and had continuity) . When I pulled one wire off the rollout thermostat ( to check it with a meter ) the blower started- why? I checked the wall thermostat and it seemed good with continuity. What do you think is wrong? Thank you

[@grayfurnaceman]

Nothing is wrong. When you pulled the wire off, you opened the limit circuit. That just told the furnace it was overheated and it turned on the fan to cool it down. GFM

[@EurekaRecycler]

@@grayfurnaceman but when we try to turn it on nothing happens.

[@grayfurnaceman]

@@EurekaRecycler Ok, Let's do some troubleshoot. We know there is power to the unit because the fan runs. Have you jumped out the thermostat at the furnace. Jumper R to W. If it starts, you have problem with the thermostat or its wiring. GFM

[@EurekaRecycler]

@@grayfurnaceman right, haven't directly jumped the thermostat terminals. These terminals should be plainly seen on the top of the control valve , correct? Thank you

[@grayfurnaceman]

@@EurekaRecycler There should be a terminal board with marked terminals. GFM

[@josephmorgan5123]

Why isn't combustion analysis talked about? I can tell someone they have a cracked heat exchanger within a minute or two of fire up.

[@markbeiser]

Yeap, well, I usually spend a few minutes eliminating other causes of erratic readings, but you can certainly know there is a problem within a minute or two.

[@mitchdenner9743]

How, excessive oxygen readings? And or maybe lower stack temps? I guess all readings would be diluted with blower air infiltration.

[@markbeiser]

@@mitchdenner9743 Rising or unstable O2 readings after the blower starts, usually accompanied by high CO.

[@mitchdenner9743]

@@markbeiser thanks , makes sense. Why does the co rise? Adding extraO2+combustion= more co?

[@markbeiser]

@@mitchdenner9743 Flame disturbance, also a breach in the HX can reduce the over fire draft and actually reduce the secondary air entering around the burner. Using a combustion analyzer I've identified breached heat exchangers that turned out to have holes as small as 1/8".

[@Farmhouse168]

I've noticed that I am getting a slight oil smell one the first floor in a bathroom. I had the furnace cleaned in the end of October, and just changed the filter myself today. The smell just started recently. The furnace is oil for heat only and probably about 10 years old at most. The burner is Beckett I believe. The last service was very thorough and the tech was here for a very long time. It's forced air. Used for heat only during cold winter months.. If it is a smell, are there other things that can cause that besides a cracked heat exchanger? I looked around and didn't see any oil spillage. Thanks so much. I have been ripped off many times on repair items so your advice is greatly appreciated. Great video also.

[@grayfurnaceman]

There are 2 types of oil smells. Burnt an unburnt. If you are getting the smell of diesel, (The smell you get when around a diesel fuel pump), you have leak. If the smell is more of a burned fuel smell (like what you smell behind a diesel truck), you probably have a venting problem. Soot blocking the venting or heat exchanger are possibilities. You could also have a crack in the heat exchanger with the burned smell. You might try looking into the barometric damper in the venting to see if there is a lot of black soot in the vent. Hope this helps. GFM

[@davidg520]

I fired an oil furnace up and smoke come out the vents upstairs,,, pulled the blower and could have put my head in that hole in the exchanger..... and I'm not sure if oil will set off a CO alarm...

[@airecraft1]

One of our customers was told he had cracked heat exchangers in both furnaces one in fall one the following winter . On the second furnace the tech gave the customer a picture of "A" crack . I searched it there was no crack , the blue dotted a/c contractor sent a second tech out , I met him there and he wasn't able to locate any crack . He did tell the homeowner his kids could die in their sleep from carbon monoxide ,while I was in the room . It upset the homeowner and we ended up replacing the furnaces there was no convincing him that his family was safe , even though I caught the contractor lying to him twice.

[@cindytepper8878]

When someone tries the "kids" scare tactic on me, I always tell them I never really liked the kids much anyway. Throws them right off their game

[@ILLUMINATORProKit]

What about if your blower motor's bearing is going (loud winning like the starship enterprise) which translates into slower fan speeds(had my blower replaced already for that reason). Will this affect a clean burn and encourage CO to show up on the PPM meter high levels out the exhaust pipe out side? I don't see any rollout or orange flame going into the primary heater exchange. My flame shoots straight into the pipes at all times even after the blower starts. Thank you for your advice.

[@grayfurnaceman]

Fan speed will not effect CO production with the exception that overheating of the heat exchanger could cause cracks. GFM

[@LexXxusTVLive]

@@grayfurnaceman Thank you. After closer inspection, I do have rollout on the right side and my high limit was tripped. Time for a new secondary replacement by Carrier under warranty.

[@johnnyprotalk3352]

I love your video “gray furnace man “ very helpful. Helps me learn how to be a successful Hvac service tech. I believe in honesty

[@Mac-i7]

Is it better to inspect the heat exchanger through the burner slots or through pulling the fan out? ………or inspecting on both ends? You mentioned it’s easier to inspect by removing the fan however I’ve replaced my fan and it appears the burner slots will be easier to access. I have a 30 year old carrier unit.

[@hvaclife9134]

its sad people try and scam people. i always bring customer to see crack or hole in heat exchangers to see if possible. my snake cam works best for furnaces

[@grayfurnaceman]

+Hvac Life Those cameras are one of the best technologies we have available. GFM

[@HucksWorld]

Looking for an answer if you can help me when we placing a furnace do I need to charge the plastic tubes that run outside

[@Puda]

The problem is that we have NO idea of what we are seeing are cracks! If you don’t do a combustion analysis, it doesn’t make sense.

[@giffy5775]

I took the heat exchanger out of my oil fired hot air heater and found no cracks after carefull inspection. I installed a new castable liner, rebuilt the burner and cleaned out the chimney. Everything works just fine but when the burner shuts off and the fan is still running, I smell burnt oil smoke coming up through the duct work just before the fan shuts off. When the burner and fan are both on, I don't smell it. Can't figure out what it could be. Thanks Walt

[@grayfurnaceman]

The only time I have seen that is when the return air has been disturbed and something has fallen next to the bottom of the heat exchanger. GFM

[@arborbreeze9884]

We rescued many home owners from "Aggressive Sales Tactics" who thought to have a second opinion. Our last rescue was a local home owner who accepted a free furnace inspection from a large company over 1 hour drive time away. She had two 19 yr. old furnaces both where diagnosed to have cracks and needed to be shut off. They showed photos & recommended replacing both units asap for safety. We showed up, showed the home owner real time video images that didn't look like the shown to her by the other company, which proved no issues with either units. This home owner was scared for her family from what she was told. We gave her a peace of mind and established an relationship from honest service. This is a real issue that affects all honest companies trying to satisfy customers needs the right way. Aggressive Selling Companies makes us all look bad, Service before Profit will win every time.

[@grayfurnaceman]

Ah, the second opinion. The bane of the aggressive salesman. Nice to hear there are honest techs out there. GFM

[@pjlaske]

My furnace tech showed me a photo, supposedly of the primary heat exchanger, with rust spots on it. The video and all the comments only talk about cracks in the heat exchanger. Is it possible that the Hex is rusty, and therefore faulty, instead of cracked? My furnace is 13 years old but the Hex is warrantied for 40 years. It seems odd to me that there is rust after 13 years if the warranty is for 40 years. It is a Bryant Evolution Plus furnace. About how much labor is it to replace the heat exchanger?

[@grayfurnaceman]

Rust could come from low firing rate or low return air temp. In any case, I would contact the manufacturer about this issue. GFm

[@MiHeatingGuy]

Good video. I have had exchangers ripped wide open and they didn't produce even 1 ppm of co. but on the other hand I have had units with tiny cracks produce over 1000 ppm. If a heat exchanger is cracked its cracked and there may be a chance of co. Older Furnaces should be inspected on a yearly basis.

[@grayfurnaceman]

+Mi Heating Guy Absolutely agree. GFM

[@georgehvac9377]

I agree. If a heat exchanger is cracked, then the heat exchanger should be replaced at minimal. Even if the Crack is not producing Co at the time of testing, it's still a defect, liability, and potential hazard.

[@Bear-cm1vl]

Carbon monoxide is only a part of the risk with a breached heat exchanger. Any of the flue gases are unhealthy and potentially toxic as they concentrate in the indoor space airstream. The breach in the heat exchanger allows the flue gasses to leak into the conditioned airstream and allows this buildup. CO makes this effect more dangerous as CO is more dangerous to humans in smaller concentrations than CO2 is, but even with zero PPM of CO, the leaking flue gasses are still dangerous to the building occupants.

[@chessdaddy0720]

God bless you and you are an honest man. I just had experienced a potential scam last week by a local highly reputable company technician. The guy spent 10-15 min down in my basement, then came up to tell me the heat exchanger is cracked. Without showing me any picture or co test. The repair cost is 3200 dollars, even with the warranty. Yet he recommended me to replace a new one. My current one is 12 years old Carrier. Let’s guess next week’s sales quote for a new furnace. I think it would be more than 10k.

[@far-out-reality3824]

in most cases i can tell if there is a crack in the heat exchanger in less than 15 minutes. they were probably right and it is cracked. this gray man video is bull, this guy is not good enough at his job to be able to tell if a heat exchanger is cracked quickly like a good tech is.

[@funkybioped]

Is there a way to ask you questions in a private "thread" email or something like that?

[@grayfurnaceman]

+funkybioped You can go to "discussion" at the channel. GFM

[@j26fremont]

I was shown a horizontal crack roughly 5 inches. No flame rollout, and between 0 and 1 for CO count. Decided to do nothing since he said it appears to have been there a long time in a 34 year old Carrier. Am I lucky and stupid, or smart and frugal?

[@grayfurnaceman]

Lucky and stupid. That is a big crack and it could warp anytime and upset the flame to cause CO. I would not take a chance of CO poisoning. GFM

[@j26fremont]

@@grayfurnaceman dead right I'm sure. Currently all CO monitors show zero. I'll monitor this winter, and save for replacement. I'm probably wrong about the size. Prob not 5". Thanks

[@OurJourneyProject]

Why can't all people be as honest as you? Thanks for the info!

[@grayfurnaceman]

Welcome GFM

[@klutch14u]

Seems like many just don't want to do the work. Plus I think a lot of these guys get spiffs on selling new systems.

[@happylucky29]

I went to commercial work to avoid the sales side of hvac. It seems residential service is mostly upselling unnecessary equipment. With commission based work you will get scams. These big residential hvac companies actually train you on how to psychologically make people think they need new equipment.

[@grayfurnaceman]

Phillip So true. GFM

[@jeniferg8492]

These creeps seek out females, elderly etc. I've been very ill with the stress and the horrible things they said to me when I called up asking what did they do to my furnace?! They mocked me........... I hope I get the last laugh.

[@wattamutt]

oh my. i know how you feel. we just bought our house in july. its sept. i had the furnace serviced today. i get a phone call at work. he is decommissioning furnace because of cracked heat exchanger. he told me exchange cannot be replaced. that i need a new furnace. $6000. oh yeah they can finance me if i wanted it. im just at a loss for words and im beside myself with anger.

[@grayfurnaceman]

I do too. GFM

[@grayfurnaceman]

I bet you have the furnace checked before you buy the next one. GFM

[@Denniss7420]

wattamutt, what happened - Did you get a second opinion?

[@wattamutt]

Denniss7420 the heat exchanger cannot be replaced. the furnace is at least 30 years old. i had 5 estimate so far. my house is 111 years old. i have no ductwork whatsover. sooooo its going to cost anywhere from 11,000 to 14,000 dollars to replace with high efficiency gas furnace and ductwork. i had and estimate for mitsubishi ductless minisplits with 5 cassetes is 15,800. someone was here today i told him how about a boiler with radiator? that would cost even more because of the pipes. closer to 20000.

[@srmay7587]

My flame roll out keeps tripping and getting tired of resetting....please help can't afford crazy parts replacement for ot but did replace high limit switch now what... same issue keeps happening : switch trips after call for heat and everything kicks on...runs good for about ten minutes then trip again so I wait for cool down manually reset and then try again...

[@Vfh........y]

most likely the heat exchanger is rotten or Cracked

[@deltat5775]

Grayfurnaceman, I appreciate your experience and knowledge and have been watching your vid's for a long time, but I must take issue with this particular one. I've been an HVAC tech for 23 years and have found many problems with exchangers during certifications and maintenance inspections. I painfully disagree with you about what you said in this video concerning how quickly somebody finds a crack indicates it could be a scam. I have a high definition inspection camera that allows me to see into the exchanger very quickly, in particular tubular exchangers and exchanges with crimp rings.Problems with these types of heat exchangers can be found very quickly. Sometimes within 10 minutes of entering the house. Maybe I'm nitpicking a little bit, but you seemed a little too adamant about that point

[@monroekunz1331]

I've been 35 years abd agree eith you. Heil furnce lot of times rings are laying on top of secondary ican pull that blower and look in less than 5 minutes. Nowadays my first check on any furnace is co level in exhaust after furnace runs for 5 minutes. Use a testo meter you can print findings and leave with customers

[@raymonddelisle6601]

I had a question. My brother has an oil furnace. Forced hot air. Always ran fine. Until one time the unit blew black soot along with smoke. Lots of black soote. Does this sound like a cracked heat exchanger? I wouldn't think it had anything to do with a cleaning. Because it was blowing this out of the heat vents in the home. Please share your thoughts. Thanks.

[@grayfurnaceman]

Has the furnace been serviced every year? If the soot is coming from the vents, it may indicate a cracked heat exchanger. GFM

[@raymonddelisle6601]

@@grayfurnaceman no it has not been serviced in years

[@grayfurnaceman]

@@raymonddelisle6601 First, clean the heat exchanger, vent pipe and do a service. This may entail replacement of more parts than normal due to the lack of annual service. These furnaces do not react well to not being serviced annually. GFM

[@raymonddelisle6601]

@@grayfurnaceman ok thanks

[@jacobdiaz6432]

potential for carbon monoxide is serious...n u replacing an exchanger in a 1980s unit is a disservice to the homeowner...give them the option of replacing

[@grayfurnaceman]

As was said in the video, replacement should be considered. GFM

[@edbrandt8972]

I am getting some flames coming out of the burner tubes. It's not a big flame rollout. The temperature above the flame rollout switch is over 400 degrees Fahrenheit. The switch is tripping now and I have stopped resetting it. My guess is a cracked heat exchanger. Can I replace it as a DIY job? Or am I crazy to suggest that.

[@tvrduude]

Been at this trade for 32 years as a service tech myself and happy to see this. Soooo many techs out there think or have been told that a cracked heat exchanger automatically makes CO. Not true. As several have noted here, TEST IT. I will agree that a crack is an issue that should be addressed, but using a likely incorrect scare tactic is what gives our industry a bad name. Now on a side note related.. for very many years I've had a "Thanksgiving theory".. why is it that turkey makes you tired on Thanksgiving..? but not the other days of the year? Ever wondered what leaving an oven (That exhausts INTO THE HOME) on for 3-4 hours while cooking the bird will do to your alertness? I hypothesize that its the long running oven and burners doing it, not the turkey. (of course does not apply to elec. ovens) Just a side observation...worth what you paid for it.

[@grayfurnaceman]

Interesting idea. GFM

[@KevinJLyons]

That "theory" of yours is listed as fact by the Godfather of CO and furnaces, Jim Davis. He uses it as an example of low level CO poisoning in his CO and fuel combustion class for NCI.

[@grayfurnaceman]

On your side note: You may be onto something there. Gas range burners do produce CO. Add to that, you could have 20 people in a house increasing the CO2, which will also slow you down, and it could happen. It would be interesting to see if the CO2 detectors installed in some thermostats for ventilation would come on. Thanks for the thoughts. GFM

[@Denniss7420]

California requires all residential have CO detectors installed - The calls are off the charts. (most of the time for low batteries). Nothing worse than seeing people use a gas oven to heat a house though, sets off the CO detector everytime and is dangerous.

[@KevinJLyons]

Denniss7420 We have the same law here in Illinois. The false alarms should only be for low batteries. Unlike smoke alarms, CO detector manufacturers intentionally set the alarms so that only go off AFTER the amount of CO becomes dangerous. If you look at the back of your detector you'll see the tolerances listed. They'll be listed as X # of ppm after X # of Minutes. This was done to decrease the number of false alarms. And it works.

[@LukeKwan78]

I think I have a cracked heat exchanger causing CO to leak into my house making me sick. I have been calling AC people to look at my unit but they keep trying to sell me a whole new HVAC system. What type of techincian/expertise do I need to be searching for to properly diagnose my issue? I see you had a meter and heard it was reading CO levels. The HVAC guy that came yesterday. Just eyeballed my unit without removing any panels. And instantly said yup it’s broke. I’m not satisfied with this. I had another person come over. He also didn’t have any tools, but opened up the plenum so he could crawl into it and inspect the heat exchanger. He said he saw no rust or cracks. But what if he missed something? Is what I described an accurate why to look for a crack? The 2nd guy said it is safe to use my furnance, but after turning it on, I noticed I began having a headache again. I”m waiting for Amazon to delivery a CO monitor to see what PPM is coming into my house. What is a safe PPM. What is not good? What is dangerous. I borrowed one from a friend and it briefly showed 46ppm.

[@johncampbell4923]

100 ppm is dangerous to health, OSHA restricts workers to 50 ppm average over 8 hours. I believe most CO detectors go off at around 70 ppm.

[@AjDexter]

I'm dealing with some of this now so this is super helpful. Thanks @grayfurnaceman

[@grayfurnaceman]

Welcome GFM

[@windelljolicoeur4641]

grayfurnaceman What about a heat exchanger cover failure

[@mmv74]

How long will a stainless steal (both primary and secondary) heat exchanger of a high efficienty modulating furnace last, typically?

[@grayfurnaceman]

I don't know of any gas furnace that has a stainless primary heat exchanger. As for longevity, many have a lifetime warranty on the heat exchanger. This warranty is a parts only one that requires considerable labor to install. You can expect 5+ hours labor to install. GFM

[@mmv74]

@@grayfurnaceman Thank you for the response. Warranty is one thing, practice another, which is why I asked. Also, most warranties are good only to the original owner. Amana makes furnaces with stainless primary heat exchanger, I have one.

[@grayfurnaceman]

@@mmv74 I have heard of the Amana, but never seen one. The use of stainless for primaries has not caught on because stainless moves heat much slower than carbon steel. This can cause excessive warpage and early failure. GFM

[@mmv74]

@@grayfurnaceman Thank you, that makes sense. I wish I could inspect the condition of the heat exchager without disassembling everything in front of it. I wonder why they don't make the back panel possible to open and access the heat exchanger that way?

[@grayfurnaceman]

@@mmv74 Because the manufacturer does not care about easy service. GFM

[@stayinthemoment18]

My furnace is 21 years old. I get it regularly maintained. Today the technician came and did his usual inspection and he showed me rust on the heat exchanger with his camera. There wasn't a lot of rust. It was just in about 5 or 6 small areas. He highly recommended a new furnace. I don't know if I should hold out until there's a crack or should I find someone who can replace the heat exhanger?

[@grayfurnaceman]

If I replaced every furnace or heat exchanger that had rust spots, I would have replaced virtually all over 10 years old. I would just watch and install a CO alarm. GFM

[@stayinthemoment18]

@@grayfurnaceman We've had a CO alarm plugged in right outside our furnace room for years so we're safe as we can be. Thanks for the quick reply!!

[@horsedaddy230]

I have a hanging garage 50 ,000 btu Reznor furnace, I had it inspected and found a very small crack almost a hole at the front that is easily seen. I checked with a magnet and the 3 fins are steel. Can I have the hole welded ? Will this be safe ? Naturally it would be done with the gas off, as its off now. Thanks

[@grayfurnaceman]

The steel used in heat exchangers cannot be welded. It will simply crack next to the weld. GFM

[@RARenfield]

Given that I have seen multiple cracks in my heat exchanger, what is the criteria for replacing the $5-7K unit completely vs. the $400 heat exchanger? The unit is a 1994 Goodman which otherwise works well. And I will be selling the house in the spring. But the service rep says replace the whole thing. I'll never recoup that in the sale price.

[@dmfb68]

The problem is this. When selling a house I believe most if not all states will require a furnace inspection before you can sell the house. If it was me inspecting your furnace and found even one crack, your funace gets red tagged and here why. If you moved out and the new owner die from CO that now falls on the company that inspected the furnace. You have a 1994 Goodman that's not that good. Replace it with another Goodman.

[@dmfb68]

Also if you can find someone to put in a new exchanger in for $400.00 then go for it because that's not a bad deal at all.

[@RARenfield]

@@dmfb68 I found a heat exchanger replacement part for $400. Labor would be additional. Assuming I don't do it myself. Is it more difficult than rebuilding an engine? If not, I have the tools. The HVAC tech who diagnosed the cracks quoted $1,500. As if. In the case of a home sale, which is not in the works now because of the Kung Flu, I would leave it up to the buyer to decide gas or electric. Then the cost would be part of the sale negotiation.

[@RARenfield]

@@dmfb68 I would NEVER try and get one over on the purchaser. That heat exchanger conversation would be early and transparent. Long before a home inspection. I nearly died of CO poisoning in that house!!! If I keep the house past summer and replace the unit, it will be a heat pump and I will cancel all natural gas services. I love cooking with gas, but it's not worth the danger.

[@robertloney393]

Two repairmen from a reputable HVAC service came to look at our cottage’s 9 year old furnace (two stage Frigidaire) that hasn’t worked for several months. They spent 1.5 hours with it and reported back to a third fellow with whom I’ve been in communication. He has concluded that the heat exchanger is either plugged or has a hole in it; he leans toward plugged. (I wonder that he should have to speculate. In 1.5 hours, shouldn’t they be able to see if it has a hole or is plugged?) He said the top door was off and assumes it had been off for a long time b/c that part was covered in spider webs. He said that with that door off, the heat that’s not supposed to be in the upper cabinet cannot escape. Apparently he thinks this situation damaged the heat exchanger. Does that sound right? I don’t think the door had been off very long while the furnace was functioning. And how would it being off prevent heat from escaping? He said the door being off might invalidate the warranty. He recommends buying a new furnace from them and gave me a quote.

[@warduke8192]

Any chance you could look at my residential furnace? It is running fine, but I'd like to proactively replace many of the parts instead of just buying a new one. It is a 2007 Goodman unit. No HVAC company I call wants this work, they just want to sell me a new unit. Thank you.

[@L2fish]

My girlfriend has an SP80 propane furnace. The tech took a part out that said went on the burner section. Didnt tell her or show her where it goes. Told her you cannot get the part any longer and left her with it. I cant locate it on the diagram. Told her its supposed to be a foot long. Its burned off about 4 inches long. Has a 2 bolt flange to mount it and is somewhat of a formed bar that must go into the heat exchanger someplace. Any idea what this is?

[@grayfurnaceman]

Its probably a NOX rod. It reduces nitrous oxide in the vent gasses. Your choice to leave it out. GFM

[@L2fish]

@@grayfurnaceman oh thank you. If I send you a photo could you identify it?

[@darrellmoody287]

Working in the basement with dusty conditions near furnace,Hot air,now living areas are dusty too,door closed,what went wrong?

[@tylerfriesen77]

A crack doesn't necessarily mean a breach, flame pattern and a combustion analysis will tell you if you have a bad exchanger. Usually you will get bad smell coming off of exhaust due to aldahydes being produced. And yes if you get roll out when the blower comes on you will more than likely have a breach. Carbon monoxide is only produced when improper or incomplete combustion is present, I have seen a full breach on a old 1960s furnace with a ppm of only 7. It all comes down to experience of the tech and sometimes it's the protocol of the company that her or she works for. If you can always ask to see certification of the applicable trade.

[@grayfurnaceman]

Mostly agreed. I am somewhat nervous about any crack, but if no CO I will get a signature recommend testing each heating season. GFM

[@markrush5013]

last winter my 30 year old propane furnance's pilot light kept going out. the guys l called replaced various parts but the pilot light kept going out. finally one of the guys came out and said there was a cracked heat exchanger and the blower was blowing out the pilot light. no parts available for my old unit.10-12 thousand to replace and add another few thousand to redo the chimney since building codes had changed. l didnt go for that and decided to add a couple more wall units...why give 10 grand for something that just burns propane when 500 dollars in wall units will burn propane too?

[@laurenconnell6590]

I had a furnace tech come yesterday because the blower wasn't working. He said it's likely an issue with the circuit board or CPU or whatever module controls that at a cost of about $800. Then he checked the heat exchanger with a camera and showed me what looked like a crack and put a type A tag on it. I did see the crack and yes it did look legit but this wasn't what was causing the finance to malfunction. It's a 20 year old unit. I'm unsure what to do, I feel like they are pressuring me to buy a new unit which probably makes sense but is this what I should do? Advice appreciated.

[@grayfurnaceman]

From what you say, I would replace the furnace. The tech sounds like he has done what is necessary to be sure. Of course you can get competing bids. GFM

[@YOPHILLYYO]

Hi I have a carrier high eff ng furnace. I just started smelling a odd smell outside. Like propane. I went to where the furnace exhaust pipe is and the smell was coming from there. I googled and it says a clogged secondary heat exchanger. I'm gonna pull the blower in the morning. If its dirty could that be the issue ? and can they be cleaned ? I cant find a video on cleaning one. I get a lot of dust down in the low basement/crawl space. And the filer is pretty dirty. Its the washable type so ill wash that also tomorrow. Please let me know what you think ? its a 2007 model 58mvb120. thank you !

[@grayfurnaceman]

The blockage is probably inside the secondary not outside where you can see it. In fact I would suggest you check the internet for a recall on that furnace. Some of these units had a corrosion problem in their secondary heat exchangers. GFM

[@YOPHILLYYO]

@@grayfurnaceman There is a billiten when i called pierce phelps for a fredit or a option to pay $800 and get a new furnce, Plus install. I took it apart and i see some rust on the back edge. Any idea what the labor shouldk cost on replacing the secondary?

[@grayfurnaceman]

@@YOPHILLYYO Its generally time and materials. Labor would be 4 to 7 hours. Materials other than the heat exchanger are minimal. GFM

[@bilga10]

Amana Goodman furnace ignitor glows but won't light up. technician said heat exchanger gone bad.can a bad heat exchanger preevent furnace from lighingup.

[@grayfurnaceman]

It could. If the crack is near the burners, it could change the air flow and prevent the burners from lighting. GFM

[@jaimecamelo7517]

My york 9 years old induce motor burn out,replaced motor the 2 pressure switches gas control valve clean flame sensor check continuity heat sensor. pay a ton of money still have no heat.brought in second repair company and got everything tested.i was told need it replace unit because internal problem in heat exchanger.any suggestions?

[@grayfurnaceman]

First, I would check into heat exchanger warranty. Too young to replace. GFM

[@genepierson1728]

Do you recommend yearly Carbon Monoxide test of a furnace? I have one that is about 17 years old. It's working fine. Other than changing the filter 3 times per year and a blower motor that failed once, it works fine but I have never tested for Carbon Monoxide. Any advice is appreciated.

[@grayfurnaceman]

I never argue with someone that wants to do a CO test. It may not be necessary but it could save your life. GFM

[@genepierson1728]

@@grayfurnaceman Good point. I'm just going to order a portable tester and use it to test. It's worth the $160. Thanks!

[@elisagoodwin9774]

I have a Vaillant boiler. It’s old but I really would like to avoid buying a new one while I’m selling the house. Suddenly stopped working. Tech said I have a crack. No other info. Can see crack when boiler door is open but don’t know if the crack location is critical and nothing was offered about a reading. What would you suggest? Don’t have a trustworthy tech to discuss this with. Thank you!

[@grayfurnaceman]

If you have crack in the boiler, you will have a flood of water coming out. Something does not sound right. If you can send pics, send to [e-mail] GFM

[@antonlavey5540]

Vaillant boilers were known to get a crack in the metal combustion chamber. Just pull the burner assembly out and its easy to see. The problem Vaillant is no longer available in the US.

[@immrnoidall]

i have a 1969 camper with a small propane vented furnace. it uses no electricity,has no fan . it is basically a metal box with a burner in it. looks like someone got it to hot and it has a crack that opens up once hot and then black smoke out the chimney. can i put some of the red silicone like stuff used on stovepipes and wood stoves, or does this need welding?

[@grayfurnaceman]

It needs throwing away. Welding will just cause more cracks and there is no silicone etc that is effective. GFM

[@mwngw]

Would a short cycling symptom be caused by a cracked exchanger? What symptoms might be seen in a cracked exchanger?

[@grayfurnaceman]

A cracked heat exchanger could cause short cycling, but usually it will cause flame rollout which opens a manual reset limit neat the burners. GFM

[@mj7728]

I have a natural gas carrier furnace in my house. The house was built in 2001 so I'm pretty sure the furnace is 18 years old. A furnace guy came out when my furnace failed to start- found out it was a couple of wires that popped loose at a junction box- but anyway the furnace runs fine and is very clean and the blower motor is nice and quiet. He said because of the age I would need a new furnace very soon down the road at a cost of $5000. How do you tell if your furnace is going bad because of age or if the repair guy is full of it? We also have a CO2 sensor in the basement within 15 ft of the furnace and one upstairs near the bedrooms. Thank you in advance.

[@grayfurnaceman]

First, the furnace in my home has been there since 1995. I check it regularly. No problem. So your furnace age is not necessarily bad. There are some models that had problems but baring that, most furnaces will last 20 to 25 years. GFM

[@alanpruett2217]

I Is it worth the extra cost in the south (Atlanta) to install a high efficiency furnace over an 80% efficient furnace, and do the higher efficient furnaces have higher maintenance cost and are they less durable?

[@grayfurnaceman]

It is probably not worth it. They are higher maintenance mostly do to condensate problems. GFM

[@DP-ez1kt]

I have a natural gas furnace. It is 20 yrs. old. I've been having it inspected since I moved here 2 yrs ago. The guy that came last year said that I didn't have to have it tuned up every year. He said that the furnace has an automatic shut off if there is a carbon monoxide leak. Is this true?

[@electriccar3253]

I have never seen one that had a CO detector built in. Keep checking it every year. GFM

[@brotherneil.]

Mr Gray, what if you have a failing motor/fan? What is the typical noise one would hear from the furnace and can it be repaired or after 14 yrs or do you recommend changing the furnace? Lennox G50-UH Elite Series. Thanks.

[@grayfurnaceman]

If the only problem is a failing fan, I would fix it. There are 2 noises that would normally come from a failing motor. One, a humming sound from the motor. Two nothing at all, just the fan does not turn. If there is a loud noise, it would probably be coming from something striking the fan blade or the blade falling apart. Hope this helps.

[@paulmerritt7540]

A failing blower motor can sometimes get louder when running than it use to be, if the shaft bearings are wearing out. If so, replace the motor.

[@brotherneil.]

Thanks Paul and Mr Gray. The technician indeed diagnosed wear on the motor's bearings and the replacement kit ran us $600 incl installation. Merry Christmas.

[@grayfurnaceman]

Merry Christmas GFM

[@hvac01453]

including install? Very Good! I've seen some Lennox motors (VFR) go over a thousand dollars our price... parts only. We ended up yanking out the VFR and installing a standard PSC motor per customer request.

[@dukefirmen3839]

What is the temp of the air on the plastic pipe going to outside on a 88% nat. gas furnace should be ? Is there a range ?

[@grayfurnaceman]

If its plastic pipe, the efficiency is generally over 90%. The 88% number would put it outside the range. If it is a 90+% efficiency unit, the maximum vent temp is 140F GFM

[@dukefirmen3839]

@@grayfurnaceman hello, I have a (Tag on furnace 75000 input and 66000 output ) furnace, = 88% efficiency to me , in my plastic v-pipe is 135-141 deg's.. thanks, I just wanted to check why sometimes the heat vapors look warm on cold days... T. Y. for a quick reply and have a great wk-end !!!

[@dukefirmen3839]

Also , should the blower speed for heat be low or med speed ?

[@grayfurnaceman]

@@dukefirmen3839 The speed depends on the ductwork. We strive for 120F supply air temp. Any speed that produces this temp is probably ok. GFM

[@tommyandtammy1]

I have an hvac unit that I just replaced the control valve with an exact replacement, but now I notice that where the flames go into the heat exchanger there are some orange flames flickering between the burners. It's not blow back because It happens even before the main fan comes on. I have checked It with my pressure meter set It to 10 for lp gas, and checked It with my carbon monoxide meter and there Is no carbon monoxide coming from the vents Into the house and the carbon monoxide coming from the outside flue vent Is only 17ppm. I looked Into the heat exchanger and couldn't see any cracks. This Is a 4 ton outside unit made by york. It is working fine just concerned about the orange flames. The flames going Into the heat exchanger are blue just like they should be. Also new Inducer motor It Is working fine. New Filter.Do you have any suggestions?

[@ottonotzl3454]

My 40 year Carrier furnace has been red ragged by gas company. I have them to check it every year, but tis was the only time I have not been present. Note on red tag reads: flame impinging, heat exchanger appears to be raptured and compromised. I hired Nexgen company. The tech did a "hydro scan" and told me it will show 100% if the heat exchanger is cracked. I was with him all the time just kneeling next to him. He said "I see the water". I asked him to show me where because I didn't see any. He said at the bottom. I ask if I can check it and I slid my hand inside of the chamber and touch the bottom. We both looked on my finger and there was no water, only little of dry rust powder. Then I slid long wooden stick to touch it all the way in the bottom rear of the chamber and again we both did"t find any physical evidence of water. Then I asked him to spray the outside of the heat exchanger more so if we can really see the water. He water it more but no water appeared. He put in his report that he saw water anyway. He offered and scheduled coming back with his boss and give another look onto the heat exchanger. But next time the tech didn't show up, just his boss came offering me a new furnace. I complained for the tech not to be right and I feel like one of the victims you are talking about. I know the furnace is 40 years old but it is still running fine. I am not sure what to do, if ask both of them to come back, do another Hydro Scan and possibly have them to measure CO at the inlet and outlet. Please give me some advice. And how should I handle gas company red tag? And none of tech I spoke knew meaning of the word "impinging". Thanks a lot.

[@thomasstuart6861]

I have a furnace in the old house with a cast iron heat exchanger. Still running, built in Preston, Ontario, Canada in 1964. That was a problem for furnace manufacturers so they came up with the new heat exchanger design which they knew could fail the day it was installed. They introduced a repair kit, if the home owners noticed a smell. The heat exchangers were acceptable to the Canadian Standards Association and the natural gas distributors because the furnace, in the same way as the gas stove, because they could prove even if the clamp rings popped the furnace does not produce CO. It only produces CO when the flame is orange and that never happens they claimed. But it does happen when the blower comes on, it can cause roll back but there has to be over 5 ppm CO for it to be a hazard. As such, furnaces are now replaced every 20 years and that was worth the BS.

[@derekkchung]

When flame rolls out on one or 2 of 4 the burners, that has to be a cracked heat exchanger?

[@Codeejonz]

i have a gibson nortek gr4gd-36k072c, during the winter the heat quit working.. so my friend that is a plumber came by and he's pretty handy with stuff like that . so he took a look and it appeared we needed to clean it. so we did that . and it was still throwing codes.. so he took more of the unit apart and we got to the heat exchanger.. i'm in the automotive industry and it clearly looked like a old exhaust pipe with holes in it..which he thinks with setting off the sensor causing it to shut down due to fumes backing up...he told me to ck the warranty and he was right. lady in customer service said it was covered. my question is now how do i go abouts processing this warranty claim for the new piece.. the lady at nortek wasn't very helpful with that part. thanks for any advice

[@grayfurnaceman]

Do you know the installing company? GFM

[@ArtistaAndaluz]

Thank you for the video. I just had a guy leave who spent 2 seconds showed me what looks like a cracked piece of metal above the burners in plain view and said it’s too old to fix and I’ll need a new $4000 furnace that they can put in tomorrow. He mentioned the CO too but didn’t test. This is the first trouble I’ve had with this 80% efficient natural gas furnace for many years. Its too old for warranty but can it still be fixed? It’s a secondary furnace too and $4k seems pretty high especially when using existing ductwork.

[@grayfurnaceman]

I would get a second opinion. Cracks in heat exchangers can be found quickly, but it sounds like you are not confident in the service tech. $4000 is not an overly high price. GFM

[@ArtistaAndaluz]

@@grayfurnaceman thank you so much for your quick reply and opinion! This same guy mentioned replacing my other furnace as well but I fixed it. I have another person coming tomorrow. I appreciate your taking the time to make informative videos and answer questions. Thank you.

[@ArtistaAndaluz]

@@grayfurnaceman I had another guy out today and he replaced the blower motor, what I told the guy yesterday wasn’t working. A $3500 savings! Thanks again for sharing your info.

[@robert.tanner7464]

5 minutes is all it took for serviceman to declare a crack in the heat exchanger was the problem. Furnace stopped and a loud humming noise was noticeable. A new heat exchanger was suggested. Should I get another diagnostic opinion?

[@rollinwithsonny7975]

Been following and glad I came back to see if that were a scam or not. Had an old Rossoe oil furnace, probably in 1950s made with retrofit parts. A maintenance guy told me there’s a crack and said it would cost 6k to replace heat exchanger because of crack. Makes me thinking…I don’t smell any carbon monoxide and furnace still working fine.

[@grayfurnaceman]

Put in a CO detector. GFM

[@rollinwithsonny7975]

@@grayfurnaceman thanks. Like you said finding a crack doesn’t take a few minutes to find it. And guess what after he change the oil filter and told me I have a crack in my heat exchanger. I’ve already got a CO detector installed nearby but no alarm goes off. Thanks again.

[@nicholasnarcowich9163]

I had a guy do just what you were talking about, except for the CO meter, that was not done. However, he did cut the silver tape into the evaporator & I wonder if I can just go down to Lows, get some silver tape, fix what was cut, & then see if the heater makes CO, because, maybe, the crack is not yet all the way through the exchanger... what do you think?

[@grayfurnaceman]

I would want to know if there is actually a crack in the heat exchanger. If the crack has started, it is all the way thru the heat exchanger. GFM

[@grumpyoldman336]

I got a call on a Payne furnace yesterday that keeps giving code 13 errors for flame roll out, and that combustion chamber is getting very hot during operation to the point it will run for 10 mins max and lock out. During start up it rolls out mainly one one side of the chamber but kind of rolls across the chamber. I checked the venting it appears clear and checked the gas pressure at manifold and it was set to manufacturer spec. The bottom of the furnace appears to have been leaking and is quite rusty but hard to tell whether it was from the secondary exchanger leaking down or a possible minor crawl space flood in the past. The furnace is not heating up nearly as much as it should i wasnt even getting 75 F from the plenum when i checked.. I did pop the inspection panel off the plenum and took pictures of the top half of the exhanger it appears ok but i cant get to the secondary from where the furnace is installed. Any thoughts on this one? Its one of the furnaces also you listed as a recall unit for this problem a Payne PG9MAB

[@grayfurnaceman]

This sounds classic for a plugged secondary heat exchanger. Any rust thru spots are hard to spot without removing the heat exchanger. GFM

[@grumpyoldman336]

@@grayfurnaceman thx for the feedback i talked to the customer again today and they have decided to let me get rid of the furnace its in bad shape and the time it would take to pull it all apart and try to figure it out... may as well get a new furnace my cost of doing that is not far off trying to repair this pos. I live in a small town rural area so my rep is everything here so always try to help folks out with good prices and they always call back to do other stuff down the road so im happy.

[@darrenmcnulty8188]

@@grumpyoldman336 changing the furnace was a smart move....check for rust marks at the back of the secondary when the blower is out and you'll see it was the right call. They've been dropping like flies!

[@user-ws2qq3gd5h]

What about pitting from rust on cells from internally to externally? Would that be a failed exchanger as well?

[@grayfurnaceman]

If there is pitting, replace it. GFM

[@johnw1868]

Does a 1983 Payne gas furnace heat shield gasket contain asbestos material?

[@grayfurnaceman]

Almost certainly not. Asbestosis was removed from installs in the middle 1970s. GFM

[@StephenMannUSA]

My Goodman furnaces are over 20 years old (GMP075-3) and one of them is showing signs of a failed Heat Exchanger. Does it make sense to replace the Heat Exchanger, assuming I can find one, or am I better off buying a new furnace?

[@grayfurnaceman]

On that model, I would replace it. GFM

[@StephenMannUSA]

I am thinking about replacing both, even though the upstairs unit hasn't given me any grief for at least a year . Do you dare to recommend a brand to buy, or to stay away from? (Goodman is not on my buy list).

[@grayfurnaceman]

There is a Trane in my basement. GFM

[@StephenMannUSA]

Thanks for the feedback. More troubleshooting. I am not convinced the Heat Exchanger is bad. The symptom was that the register nearest the furnace never saw above 80°F. But the matchstick test showed that there was no air coming back through the HE, so no cracks. I also checked the limit switch- it never opened. I was really scratching my head as to why was the gas being shut off after 30-60 seconds of operation. (The short burn is apparently why the nearest register never got over 80°). I jumpered the white and red at the controller board and the heat ran as before, 30-60 seconds then off. This was getting stranger. I don't know why, but I went to the thermostat and removed it from the wall mount. Suddenly with W-R jumpered, the furnace came on and stayed on. Very strange. I wired in an older Ritemp thermostat and the system seems to be running just fine now. Since I have identical systems in two zones, upstairs and downstairs, I put the "failing" downstairs thermostat upstairs, and that furnace seems to be just fine. My next test is to remove the Ritemp and plug in the Honeywell from upstairs. If everything is still working, then I can relax. But if the downstairs still won't work right, then I am going to be puzzled why it doesn't like the Honeywell thermostats. I like the Honeywell thermostats because I can control the temperature through my Amazon Echo units. Oh, BTW, what is the white ceramic component behind the gas valve on the GMP075? Is that the connection to the ignitor heating element? (It's hard to see behind the gas pipe). Thanks again.

[@grayfurnaceman]

Some electronic thermostats will not work with the electronics in the control board. You can install an isolation relay to separate the 2 components. The ceramic component is the hot surface ignitor. GFM

[@DeWittPotts]

Most of what I have observed from other HVAC people is that they will look for 'blowback' or roll-out when the furnace is running. If there is blowback or the flame rolls out from one or more of the burner ports when the blower fan turns on they they will assume that the problem is the heat exchanger and recommend replacing the furnace.

[@grayfurnaceman]

That's what I use as much as I can. Checked with a CO detector. GFM

[@mikemalone6103]

DeWitt Potts we don't go checking heat exchangers in most part because of the time constraints. If we are doing an initial inspection or evaluation of the unit or during a pm we notice the flame dancing, flame lift or other abnormalities we look further. One time, I was doing an AC pm, and while walking past the unit exhaust pipe, I felt a current of air against my arm. Startled, I knew from the sound that the blower motor was on. Looking further, I popped the top to see a few large slots in two of the tubular runs of the heat exchanger. This unit had a positive pressurized heat exchanger. Being summer, I killed the gas and control wire from the stat to prevent heat. Of course the customer waited for a real cold day and continuous staff complaints till they did something, and then it was hurry up....😠

[@grayfurnaceman]

Don't you love it when they do that. GFM

[@hvac01453]

yes 3;30 on a Friday the calls seem to come in for problems that occurred early in the week like lets say Monday morning...

[@waytospergtherebro]

USB borescopes are under $30 now so they usually go with "I can't work on anything that old and the new model won't fit there so we'll have to put everything in the attic where you can't see what we're actually doing for $20,000" instead.

[@ittech7967]

Thanks for posting this. We have one like it and seems to have some flame roll back. The flu vent is clear, How would i check for cracks? Thanks again