Combustion test to determine if the heat exchanger is cracked

[@Josh-px6xb]

I was told You can hook up a manometer to the inducer inlet port , zero it and turn the blower on. You should get a reading of there is leakage in the heat exchanger

[@lizards7777]

Sounds logical

[@edgarallanbro9624]

I’ve never used a combustion analyzer. usually pull blower , and act like I’m trying to escape prison! I like to get a photo for the customer and they can also help pull me out when I’m stuck! lol

[@sydsyd]

When the doors are off the furnace, it is getting much more air.

[@Slavelife9279]

It’s a vented combustion chamber on a 80% furnace, the door off will make no difference on the test.

[@Hugo-py2ce]

Whats the static on the return and supply? Whats the temperature rise? Was the heat exchanger inspected with camera or pulled to thoroughly check for cracks. This is important, it's just not the analyzer. I've had a perfect analyzer test with my testo, but when heat exchanger was thoroughly checked there was a crack/fracture in one of the chambers. Don't just go off of the analyzer test and say it's perfectly fine. Do more work, it's important. All this video does is make someone look bad if the heat exchanger is cracked. By the way I have 21 years experience not just someone giving their opinion. Thanks and happy diagnosing!

[@Slavelife9279]

You don’t check total external static pressure on a gas furnace return to supply, you test at the blower compartment after the filter and before the evaporator coil after the heat exchanger.

[@tonyd4346]

Pretty quick to call someone a liar rather than inexperienced. Especially when we can point out some mistakes you are making.

[@carlossaenz4075]

U needed to explain what the levels and ranges should be and where did u get the information

[@dwj7386]

Lennox has flame test for heat exchangers that doesn't involve holes.

[@Aquariun9iteMMare]

If I'm telling a customer you have a crack in the heat exchanger, which means fork over $2000, I should bring them proof and not just my word. I'll either show them on my mirror or a pic from the camera.

[@mystory1162]

I'm going to quote this under chapter 7 titled "combustion". Page 7-28 under "corrective action attempt to visually find the crack or hole" It reads as follows under step B. " on the service invoice, right that you're testing indicates a leak in the heat exchanger.( do this even if you cannot find the leak.)" They're not intentionally lying they're told to do this. Argue with the manual do not argue with me about this matter.

[@mystory1162]

Procedure: 1. Follow the manufacturer's instructions to properly zero the combustion analyzer. Insert the combustion analyzer probe in the flue pipe. 2. Stop the furnace and observe the oxygen reading for stability 1 through 3 minutes. 3. When the blower starts, watch for a change in the O2 reading. If the O2 reading goes up, there is a leak. . Has nothing to do about what you said in your video it has to do about oxygen levels going up after they have stabilized when blower fan comes on.

[@98pappa]

Just a sales push, furnace is in good condition

[@networth8754]

So many dishonest HVAC technicians out there.

[@nickecribb]

Not sure what state you're in but in SC you have to render the unit inoperable with any crack or hole in the heat exchanger

[@michaelm7874]

You are supposed to run the furnace in it's most natural state of operation. Leave burner door on anotherwards

[@hozerhvac4406]

yah good question. what was the CO reading.

[@deloct]

Thanks for sharing! nice explanation on the analyzer results Sr.

[@notanewbie1718]

Do you think a combustion test is 100% accurate in the case of small cracks? I worry about that.

[@glenng2282]

Absolutely not, this test will not find very small cracks!

[@rodgraff1782]

@@glenng2282 I’ve also seen closed cracks that pop open after running for 1/2 hour. I had one old furnace with a pilot that kept going out. I sat there with it running, and the flame looked normal. Then after about 1/2 hour, the flame would roll out. Right when the furnace burner was shutting down, the roll out snuffed the pilot out. After changing out the furnace, we found a fairly large closed vertical crack, that opened after the furnace operated for 1/2 hour or so.

[@stevenmachnick9613]

Disagree..... All you are saying is that if there is a crack, it's not leaking air into the HE. The only way to ever say there is no cracks is visually inspect the HE. I'm the guy that goes back after you and the last company was there and proves there are cracks and shuts them down. Gotta be 100% on every call. Just saying

[@raymondtakeall4803]

Exactly!

[@its_bob_from_accounting801]

spoiler alert,the meter wasn't calibrated correctly

[@rockdean1]

Did you address the water leak in the evap coil?

[@cobyackerman6935]

You need to take the NCI Carbon monoxide & combustion analyst training certification. You didn't look at CO and you don't tell what O2 range is supposed to be. It is actually under firing at 11% O2. And what is oxygenation you keep talking about. You have a lot to learn about combustion. One plus for you there is no problem with drilling a hole in Bvent, It's a negative draft furnace. You would never leak out combustion if you never sealed the hole, unless you have plugged chimney.

[@markhoffmann5941]

negative pressure on the inlet side of the inducer fan motor and a slight positive pressure on the outlet...

[@trevorhowell5273]

This is a fan assist unit, fan is made to overcome the restriction of the burner only (not the venting system). Bvent is NEVER positive.

[@brentjkunz]

where can you take the NCI carbon monoxide & combustion analyst training at?

[@eddymumford4086]

my Goodman 80 percent gas furnace flashes 2 0 when running only when it's running it's been working ok no problems YET 🤔 my heating pro guy doesn't even know what it means

[@ernestodiaz76]

Never drill a hole in a v vent pipe

[@blmkintaro]

How are you just going to ignore all the rust spewing out the bottom of the inducer chamber?

[@jeffstack4217]

Don’t be stupid. That’s obviously condensate from a leaky evaporator that dripped into the secondary drain pan. Besides, there’s no such thing as an ‘inducer chamber’. It’s an overall crappy install, but wouldn’t expect much more from a Goodman dealer anyway.

[@russelllieser4226]

Smoke pipe? Drilled throw double wall?

[@bryceelmore8190]

Nice video. Do you do a combustion check on a standard pm? Or just when you make a repair

[@thomasnoland6559]

Learn how to use a combustion analyzer 11% is to high. Do you know why? Doubtful. As many of you “ technicians” aren’t technicians at all. You can use the analyzer to set the gas pressure! What was the total ESP??

[@shabba3602]

11% of what reading exactly is too high? Going through this issue myself currently. What gas are you referring to? Thanks

[@tylerfabish5578]

@@shabba3602 oxygen. 11% oxyge

[@denrayr]

It's probably being being under fired. I'd like to see the c02 reading and stack temp to verify, but you can see the flame looks a bit weak. The gas pressure needs to be bumped up a bit, but might not be totally necessary if stack temp is high enough.

[@deloct]

What should be normal co and ox readings if heat exchanger is working properly.

[@randomdude5968]

Octavio Delgado it should be CO2 6.5%- 8%

[@johnwhitehead5457]

@@randomdude5968 10 to 11.

[@tylerfabish5578]

@@johnwhitehead5457 10 to 11 for oxygen? I was wondering the same thing. Im a young tech and for some reason ive been struggling to find this info

[@johnwhitehead5457]

@@tylerfabish5578 10 to 11 for CO2. If you're in the business you need a combustion analyzer.

[@Slavelife9279]

Per NCI- oxygen 6%-9%, CO- 99 ppm or less after a full 10 minute cycle performed 3x’s. But usually the CO won’t be above 35-50ppm if everything is in order(burners clean, aligned properly) etc.

[@erikrezlman7900]

I couldn’t tell what combustion tester you are using in the video. Would be willing to tell me? I like the compactness of the unit. Great video/content Thanks

[@chestercopperpots392]

Fieldpiece

[@happylucky29]

The SOX3 checks CO???

[@lancerudy9934]

3.5 inches of water colum.

[@Dave-nm3xc]

Nice to see someone with integrity going behind shady contractors trying to scam customers. Nice work!

[@michaelpaulzdaone]

What was ppm in co? What was efficiency of that 80%furnace - you do not just set gas pressure to 3.5 - you check efficiency! Total waste !!

[@FXDLS-ot1wq]

Why does it read 108% efficiency? Shouldn’t it be like 75-80% on that furnace?

[@bretth1760]

EA = excess air

[@TheManInaHat]

Co is different than co2 my guy

[@lancerudy9934]

What is the co range?

[@deltat5775]

Indisputable?

[@u157391]

Shouldn't be O2=6-9% and EA=at about 40% for Natural Gas?

[@CombatFIFChuck]

That's what i though. 3.5 w.c. might be under fired for this furnace depending on heat content

[@tylerfabish5578]

@@CombatFIFChuck 3.5 IWC is generally how natural gas furnaces are fired

[@zack9912000]

@@CombatFIFChuck Not correct NG is at 3.50WC unless you have a two stage unit. Low fire typically is 1.5 high is 3.5

[@Rotaris1]

no co reading?????

[@geoffpacker1582]

I strongly disagree with not shutting down any furnace that has a crack. Remember, the tech is legally as liable as the company.

[@skipd9164]

I agree you cant leave a heater with a crack. Ive had people throw me out and had to cell FD and they would get me in to shut off and be proof about call. If you left on and someone died they would go after you in a heart beat

[@zack9912000]

@@skipd9164 As soon as I find it unsafe I remove the control board and put it off to the side. Kill power and shut the gas off. If I know the homeowners are going to run it anyways, I take photos and include it in the detailed report. So when the FD calls we can point to it

[@skipd9164]

@@zack9912000 Zack When I was a service representative it was different. No cell to take pictures with and stae regs said it had to be locked off. I have a few stories of landlords trying to get a heater going at any cost. I wouldn't do it for any amount. Each state is different but a real bad unsafe condition. I would cover my ass. People lie quite a bit. Someone getting killed or hurt real bad they will find legal counsel to blame anyone but themselves

[@rodgraff1782]

@@zack9912000 Don’t just shut off the gas. Cap it off somehow. That is what the gas company does in our area, if they find an unsafe condition. Then they red tag it.

[@edt.5118]

There are very few honest hvac companies out there. A scam hvac kid (maybe 3 years experience) shut off my heater and never took off the cover to inspect the burner flames, and never checked for CO2 anywhere on the heater. Finally got an authorized tech from Trane who checked the entire heater (4 days later), found zero C02 and found no other reasons to shut the heater down. Avoid private-equity investment owned HVAC companies.

[@bobgallo2178]

Always set the gas pressure at manufacturer's specs. You were checking for co in the flue, should have been checking the air in the plenum. I just retired, company that I worked for uses a smoke pen, which is approved by all manufacturers. You young techs need to consult with the company reps, most have very good tech support.

[@stevenmachnick9613]

I disagree and agree. I rarely set gas to manufacturer specs. I find 100% of the time gas needs to be set based on static pressure.

[@rodgraff1782]

@@stevenmachnick9613 Static pressure has nothing to do with gas manifold pressure. The correct way to determine manifold pressure is to clock the gas meter, find the heat content of the gas in your area or use 1050. Calculate the btus input, and compare with the furnace data plate. Otherwise you don’t know if the furnace is over fired or under fired. You can usually adjust between 3.2 and 3.8. And get it, as long as no one has tampered with the office size.

[@stevenmachnick9613]

@@rodgraff1782 again agree to disagree. Your theory of setting gas pressures has called me to many homes for return trips to set gas pressures properly. Also static press is the most important variant in fine tuning a furnace. I appreciate your a retired tech but many of your tactics are obsolete.

[@rodgraff1782]

@@stevenmachnick9613 Steve, I realize static pressure is an important reading, and we always take that, along with temperature rise, to check the airflow and ductwork. We don’t clock the meter every time. It is used as a diagnostic tool to see if a furnace is over fired, which can cause overheating, and if found to be over fired, can cause a cracked heat exchanger. Clocking the meter is the only way to tell if a furnace is running at the gas input, in BTUs, that is listed on the data plate. The gas pressure can be adjusted between 3.2 and 3.8, to fine tune. High static and temperature rise has more to do with airflow, and restricted ductwork, and adjusting gas pressure to compensate for bad ductwork is just covering up the real problem. I am a retired tech, but I have been teaching Union apprenticeship classes for over 30 years. Clocking the meter would not be in our current curriculum if it was a bad or outdated practice. It is a requirement for all students to know how to do this. I’m not saying it would be your first course of action if a furnace is overheating, but it is a good tool, if a furnace is still running hot, after checking the ductwork for proper static.

[@Gasparifanboy]

what is the make and model of that analyzer

[@lancerudy9934]

What is the range?

[@rubybutler373]

how do you do a combustion check on a gas pack

[@CombatFIFChuck]

Stick the probe down into the exhaust before it reaches any outside air to dilute it. Easier on some than others

[@chadpadilla2664]

I believe that checking for CO in the supply air plenum will give you the best results. You will always have CO in the exhaust vent because that is where it is supposed to be..

[@jmaldonado741]

😂

[@briansword2641]

Perfect blue flame?? Blue flames kill people just like yellow flames. The amount of CO the appliance is producing is all that matters. Gas pressure at 3.5 also means nothing. This furnace is underfired.

[@armandmelch8110]

Dude, you drilled a hole on the B-vent pipe! I hope you replaced the damage section you drilled into. You cannot seal it and now you have Co pouring into the attic.

[@geoffpacker1582]

Yeah, who drills bvent?

[@skipd9164]

Put a sheet metal screw

[@arkanoiddude]

First off, you can drill b vent for combustion test, use a step drill bit...drill a 1/4" hole in the inner layer, drill a 3/8" hole in the outer layer. When finished, use high temp silicone to plug inner hole, and use metal cap to plug outer hole. Multiple b vent manufacturers have stated that its acceptable to do this if you plug the holes correctly. Second b vent flues operate under negative pressure so more likely that room air would be sucked in instead of flue gases leaking out. Third, if furnace is operating correctly than you should barely have any CO in the flue to begin with.

[@primusheating1]

Couldn't explain it better than you just have. Keep up the good work.

[@GoogleUser-mm5im]

Armand Melch you obviously don’t know, so it best to stay quiet or ASK if it’s acceptable.

[@kodiaktheband]

Cut yours nails 😅