Service Call | How To Diagnose A Bad Gas Valve

[@bills6946]

Exactly right. Many guys slap in a new valve, run a cycle, take the customers check and leave. Always check output gas They are set higher at the factory to ensure ignition in most scenarios. High gas will make the furnace run hot, possibly causing hi limit shutoff and even shorten the life of the heat exchanger. You are a technician, sir.

[@kingvick5914]

Were can I get that pressure checker

[@yanzhang98]

Not everyone has a pressure checker.

[@rorynelson7548]

I worked on one last night, board was sending power to gas valve and operating correctly. Checked output pressure side, nothing came through

[@cleansebob1]

I was wondering if we need to adjust the pressure when ALL of the gas appliances are on, so that pressure to furnace doesn't drop when that occurs? Or am I overthinking it?

[@rorynelson7548]

@@cleansebob1 yes you are supposed to. It will say to in the manuals too. Depending on how many units are gas in a house, I may not worry about it because there's typically very little drop in pressure with other units running

[@stevemiles5012]

SO thankful for this video! HVAC contractor said I need a new furnace and immediately sent out a salesman. After telling them I wasn’t interested I tore into myself and was able to diagnose and fix the problem. This video helped a fair amount. Furnace will eventually need to be replaced but for now this saved me thousands!

[@yuyuyu9029]

Hate sales man in blue collar jobs

[@5838Crestgrove]

How old is your furnace ? Did you do a flame test ? I don't trust contractors as far as i can throw them, but if you have a cracked heat exchanger, you should indeed replace your furnace. It is dangerous.

[@fonzario]

Thank you for the video. Helped me diagnose my problem. I was just about to order a new control board when I saw your video. I was able to isolate the problem to be my gas valve. I was unable to get a 24 volt measurement at the out of my board until I disconnected the wires from my gas valve and measured it that way. That told me the board was doing its job. Inducer motor, pressure switch and igniter all performed fine. I ordered a gas valve online because outlets in town will only sell to HVAC contractors.

[@joedixon8804]

Good video. I been a resi installer for six yrs now. Trying to switch to service. Gonna replace a gas valve and control board on a 90% amana tomm

[@druwoodson3494]

Great video, needed a good refresher since I don’t repair many units being an independent handyman. I am HVAC qualified, few jobs in between. Thank you…

[@bigpaul7085]

This video really helped ! I heard the audio click, but that must have been from the mother board ! I will test the wiring and determine if in fact it is a faulty gas valve !

[@dblackkw]

Excellent technician! I liked and subscribed. I don't have any issues with my heater and I am an oil heat tech but know very little about gas so you are my "go to guy" thanks for being professional keep up the great work!

[@waynevaughn3107]

Thank you ! So helpful. Helped me pinpoint the gas valve and find corrosion on the terminals cleaning them got it working again! Thank you so much!👍🏽

[@samyz1660]

Amazing gas valve video. I do have a request please. I'm a new tech , I came across valves not sure where to plug my manometer. Could you please do a video of different gas valves and their port to connect. It could be just a pictures of valves. I like the quality of your videos and most importantly, you show the step by step process. Thank you.

[@marcusdarnell3348]

Great video! It is easier than I thought to replace an gas valve

[@roqueherrera8471]

So I been doing install for 16 years and now transferring to service 🙏 for the knowledge…….

[@hughghiringhelli6657]

Excellent video... nicely done and so very helpful!!!

[@paulhu1358]

Thanks!

[@dporrasxtremeLS3]

Field Pulse... Great Video! To the Point! Very enjoyable! You are very easy to follow! Subscribed awhile bad because of the great content and easy to learn! Thanks Josh!!!

[@HVACTechTips]

Awesome, thank you!

[@cleansebob1]

Excellent! Had an intermittent yesterday which cost me a control board, but, oh well...

[@elleondejuda4681]

Very good explanation my man God bless you

[@paulericn.mouafo6610]

Really helpfull tutorial.. I'm entangled in such issue with my boiler i was even considering to change it. now it looks different. Thanks so much

[@rhettlyerly545]

The video is excellent. The only point that I would add is that you should almost always use pipe wrenches in pairs. Tightening or loosening a pipe with only one wrench puts a lot of stress on the rest of the piping system and equipment.

[@spook283]

hey, i want to thank you for your help. your video saved me around a 1000.00 today.woke up to a cold house called the company that installed my furnace, they told me 198.00 for the guy to come out, 550.00 plus for the gas valve and another 2 to 300 for the repair. called grainger supply got the part for 130.00. they that company must think i was born last night. its a total shame how they take advantage of some people who have no idea.

[@HVACTechTips]

Yep. I see it all the time. Glad I could help

[@ZacharyMarshall-p4e]

$850 to $1000 is what I charge, not taking advantage of customers. It’s the cost for a professional service. Glad you figured it out and saved yourself some money though.

[@5838Crestgrove]

you luckily had one of the cheapest valves out there. A smart valve would have cost you 3 times that. You pay for the knowledge and experience, not the actual work. Even the honest contractors aren't cheap.

[@tylerlivengood9970]

Make sure to check incoming gas pressure before final diagnosis. Most gas valves are internally checked and will not open if gas pressure is too far off. Not super common, but does happen.

[@5838Crestgrove]

i was wondering about that. Checking gas supply and orifice condition seems like smart preliminary checks before doing a valve replacement....

[@Mokelso78]

Thanks for the step by step instructions

[@yonasserdo5320]

Thank you for this important and impressive knowledge you’ve shared

[@edbard3766]

Wow, just fixed my gas valve. turn the gas screw half turn, turn it back to same position works just fine. Crazy

[@ernestalfa9045]

Dude that was a great explanation 10/10 good job keep it up

[@HVACTechTips]

Appreciate it!

[@jorgesegura7333]

Excellent job!! Quick and easy!!!👍👍👍

[@delu534]

Thank you for the video. Our furnace works fine as long as it gets a break between uses of around an hour. Tech said it was the "Smart Valve" which will cost around $1000 to replace. Anything else it could be? Why would it still work when it gets a break but not fire up if you try to use it without enough of a break in between?

[@ZacharyMarshall-p4e]

It’s just working intermittently, around $1000 is the going rate for gas valves. $850 to $1000 is what I charge.

[@Nosirt]

@@ZacharyMarshall-p4e1,000 for a gas valve replacement? There’s no way it’s normal. Most peoples gas valves are around 100-200 dollars at most.

[@msalazar89]

Also do the regulators come pre set to a specific gas psi?

[@losmoore3358]

Looks easy when u have the right tools and gadgets. Especially that plastic hose connected to that digital machine. Did u put plumbers puddy and plumbers tape on the pipes ?

[@maheradous9257]

Good job 👍

[@soloch69]

Great video keep them coming 👍🏻

[@HVACTechTips]

Thanks, will do!

[@manonfire3642]

Valuable video and well explained. Thanks for sharing.

[@HVACTechTips]

Glad you enjoyed it!

[@robertoescobar007]

You're the man, respect for a great video and great explanation Sir. thank you! 🙌👏👏

[@kenwhitehead5130]

Great video... I tried everything in your video and still no help. I actually watched several other videos on diagnosing your HVAC system to no avail. Well, I was about to give up and call a serviceman for repair. Then my wife started making lunch and noticed there was no gas to the stove. I remembered we have an automatic shutoff on the outside gas meter. We live in earthquake country so I installed this valve 30 years ago. We recently had a swarm of earthquakes and the valve shut down our gas line. A quick reset of the earthquake valve and everything was up and running again. No harm no foul.

[@cowgerbry]

Excellent, very helpful, thank you!!!

[@josemena7644]

Thank you for the details!!!!!!!!!! Great job:)

[@InsideOutElectronics]

Good video ! Thank you What if 24V to the gas valve is applied only for 1 or so second, Obviously no gas coming out and igniter is off in another 1-2 seconds. Wondering what does it mean ?

[@pinpom774]

What type of sealant do you use for the gas pipe connections?

[@Alex-y2p5u]

thank you very much for this video

[@tillerdogg3232]

Good video man. I forget to turn gas back on all the time😅

[@turborsx5740]

Thank you for this video! How long does the 24V stay that way after the valve opens? Thanks in advance!

[@richardfluty3215]

Is it a necessity to adjust the valve allways? Or are they generally in spec from manufacturer

[@HVACTechTips]

There usually close but it's recommended to always check at the first start up

[@jashimuddin7716]

Thank you very helpful video

[@michaelrothman4602]

Thank you for the videos you are very talented. How do I find out the required gas pressure needed for my boiler?

[@HVACTechTips]

It should be printed on the valve or on the nameplate of the boiler.

[@bills6946]

Look at the name plate. The information is on the plate

[@jaimegonzalez6926]

Very well done awesome video.

[@lisabennett5078]

Good video, thank you!

[@pablobon5957]

Amazing video thx man

[@Ray-wr2wr]

are replacement gas valve comes factory set up at 3.71 iwc ?

[@menymartinez4238]

Like you manometer bro question where did you buy that manometer pls

[@nicholassharp8691]

Music blew my ears out then I could barely hear you. 😂 All good though. Thank you for posting.

[@Talentman18]

Thank You!

[@David_Poole]

The junk single stage Honeywell has valves with a grey top and small red switch will give you 24 with the leads unplugged, but when connected with short out the furnace, shut it down, then it goes into a retry. If you test for voltage with the leads hooked up to the valve, you'll always see zero. Leading you to think it's a board. Also, I rarely see a 36J go bad. How often do you run into a failed 36J?

[@westonwatts6606]

I like this guy!

[@impartiendovida2377]

Muy bueno gracias Very good thanks

[@x426x]

How do you test for 24v on a two stage valve. They have three wires.

[@ForThePeople.]

This should be covered

[@davidphil6708]

Thanks for the explanation. My gas valve is getting 13v before the board sends 26v to it. My HVAC guy replaced the board and flame safety sensor and it did the same thing. Could this be the gas valve going bad or do I have wiring issues?

[@HvAcAprentice]

Nice video!!!👍👍

[@ValorieAF]

Good video, but what is the size of the tube adapter did you use? I have the same valve but I am not sure what size tube I need (although I guess I could try to fit a caliper in there to measure it...)

[@jorgedelaossa9899]

Thank you so much

[@josereynaga]

Hello friend, I have a question, my heater turns on but after 5 to 10 minutes Riley cuts off the gas and after 5 minutes I open it again and it turns on again and I changed the flame sensor and it does the same to me. It will be the tablet that Riley already it does not work

[@englewood1961]

Use a sharp probe on the high and medium. jumper the high to medium and with the dammit switch taped on, use an alligator jumper from the R redead and put 1 24VAC ion the jumpered high and medium, listen for the click and the gas flow.

[@gp3yt]

For the DIY homeowner, can the CAT85 Manometer be rented? Obviously needed for tuning the GV. Buying a gas valve is one thing... but if you have to buy a CAT85 Manometer... $$$$$ big bucks for just one time use.

[@stevenyoungheim4837]

Question, what if the fan comes on, the igniter comes on, the burners light you have air movement but the heat coming from the vents is only lukewarm?

[@yami4g63]

My issue is.... I have a Armstrong ultra sx80. It will light the pilot fine but wont always light the burners. When it does light the burners the time they are lit is random. Sometimes just a puff happens... sometimes it lights good burns for 4 sec then cuts, or sometimes it runs a full cycle, but never 2 times in a row.

[@TimMetling]

How about a Lennox two stage gas valve? How do you know it is going into high fire?

[@mousetowndude]

Nice video Josh! Thank you for the time and effort to help others. I'm retired from the trade and remember when I was green at it, circa 1960, and needed this kind of help [ long before the internet existed]. Took me a long time to get up to your level. My tip is that a service tech must keep in mind that an intermittent sticky gas valve can render misleading error codes such as "check flame detector rod" or "check ignitor" when those things are perfectly fine. Intermittent troubles can be challenging for even an ace tech. 17Apr2023 8:02 PM ‹(•¿•)›

[@HVACTechTips]

Your spot on. Thanks for the great information. I appreciate the compliment. Like you, I never had this type of advice or help when learning this trade. That's why I do these videos. Having something like this would have been such a huge help for me. Thanks for watching.

[@cashewABCD]

My switch on the valve failed. Ohmed the little circuit board. Found the pins for the on/off mechanical switch and let's just say it works now

[@EdwardNg-fl9tr]

Is 3.5 the right gas pressure for all furnaces?

[@drcornelius8275]

Was just going to ask the same thing.....

[@maheradous9257]

Good job

[@johnnyg6448]

I got a new trans unit installed early this year , first time trying the heater and it ignited when it wants . I’m assuming it might be the valve

[@michaelmendez4909]

How do I know which gas valve I can replace with if I can’t get the original one?

[@jemlyn67]

I can never find a video that shows a gas valve with a molex connector being tested. What do you do when the gas valve wires can't be pulled out separately? 😮

[@billrowan1957]

What if the 24v isn't sent to the valve?

[@mikecabral7436]

Could a bad gas valve cause roll out flames?

[@bills6946]

Cracked heat exchanger is the usual cause. Verify by taking CO readings at supply vents in the home

[@bernardocisneros4402]

Have you ever had the same situation that's in this video, and after replaceing the gas valve with a known good one, the furnace still doesn't light?

[@tomhill9445]

My valve is stuck shut. Its getting 39 to 40 vac. Is that too much ? Could that cause the failure ?

[@emmanuelsurf]

How can you test the gas valve if 24 volts are coming in, gas go out and flames stays on for 4 seconds and then it shuts off? I already cleaned flame sensor, checked for roll out switches continuity, checked for any lose ground , flame ratification voltage checked, heating exchange checked, pressure switch voltages in/out checked, capacitor, blower checked, exhaust pipes checked, board has been replaced and voltages have been checked, gas valve coil is good also tested with multimeter. The only thing left I can think of is the gas valve board or malfunction but not sure. I got a new one replacement gas valve but it’s smaller than the old one and I have to get a bigger gas pipe. What else could be causing the flames to go out after 4 seconds that i haven’t mentioned above?

[@StevenHill-l6g]

How did you know it was suppose to be set at 3.5? Where do we find that info for our furnace>? That kind of info would be nice in the vid.

[@HVACTechTips]

It's on the top of every gas valve.

[@bills6946]

Look for the label in the furnace. It will tell you. 3.5 wc is a rule of thumb. The manufacturer gives you the exact water column needed for optimal operating temperature, safety and efficiency

[@SSintox]

At (3:40) what are the 2 nifty pipe wrenches you used? Looks like a monkey wrench but ratcheting? Thanks. Also, what does it mean 1.5" W.C. written on a gas valve body? Also some gas valve on amazon says "for 1/2 x 1/2 pipe", some don't even mention the inlet/outlet pipe diameter. Is half inch a standard size for most gas steel pipe like the one you have on video? Those home steel pipe look larger than half inch though that why my question. Thanks again.

[@charlesmalinoski6325]

The size of the piping is relevant to the BTU output. But yes.1/2 inch is pretty standard for a residential home furnace.

[@rhondawestaway626]

Will a furnace run with a bad valve?

[@rocker8692]

No combustion analysis?

[@austinreeves5221]

My spa heater just stoppe working. I am getting power to the leads so Im guessing its the gas valve. Hopefully it fixes it

[@Hvacmania]

Aren't you supposed to check a relay also?

[@bobshanery5152]

You should check the pressure of the gas before replacing the manifold. Its not common but can happen. The supply could be blocked or not even getting gas.

[@oso1165]

You have a combustion analyzer right in front of you but you weren't checking combustion as you were setting the gas valve outlet pressure ???

[@HVACTechTips]

Lol. That wasn't the point of the video I was making. A full combustion analysis was done after I filmed the gas valve replacement.

[@oso1165]

@@HVACTechTips gotta do it when setting gas pressures no?

[@HVACTechTips]

No not always but it's recommended. Most technicians including myself aren't always allowed the time frame necessary to do a combustion analysis on every furnace.

[@engineer1793]

Must of been hot in there, see your arms were sweating

[@HVACTechTips]

Yes. It was. 😂

[@slakjawnotsayin5451]

I have to ask, why didn't you do the pressure test with the meter and try adjusting the valve under the brass screw cap, before swapping the entire pressure valve assembly? Just seems kind of odd that the whole assembly would need to be changed out, when it could just be a corroded valve or something in there, that could possibly be tested and adjusted?? I have no idea, but I couldn't help wondering that while watching the video... Are they that cheap, that there's no point in bothering with that, to avoid a future service call or something?

[@crs1474]

Voltage on my valve jumps all over the place when the board is sending signal/voltage to it. Goes from -100 to the -190s. My multimeter is set to ACV200 setting. I switched the leads on my multimeter to the other prongs on the gas valve and same results. Does that mean my control board is the problem? It’s a RHEEM rooftop furnace.

[@KHAOE1]

Same here. My ignitor sparks but no gas. When I tested the power to the gas valve the numbers on the multimeter are all over the place when the ignitor sparks. I'm thinking my control board may be bad. Have you found the problem yet?

[@crs1474]

@@KHAOE1 Somewhat temporarily fixed it. I removed and reconnected the harness connector (the block with 9 wires) that is connected to the control board, blowing out any debris that might be on the pins on the board and connector. I made sure it was seated firmly into the board. For now that seems to be the fix until I can replace the board. Make sure you remove the breaker going to the furnace. This is on a Rheem roof unit.

[@KHAOE1]

@@crs1474 thanks.

[@crs1474]

@@KHAOE1 no problem. Side note. After about a week my furnace started having the same issue but disconnecting and reconnecting the same connector fixed it again.

[@KHAOE1]

@@crs1474 got it...if I replace the gas valve (Already have one on order) and it doesn't fix the problem I know it has to be the motherboard. My problem first started when it started getting cold outside (My furnace is on the roof). My furnace would not work at night but just fine during the day. I think the motherboard needs to "warm up" or something before it starts working right. Maybe need more insulation inside the unit.

[@msalazar89]

How much would this cost for a tech to come out and do this

[@HVACTechTips]

$400-$700

[@michaelcolovos3834]

​@@HVACTechTips is that including the valve? 400-700. also why the 300 spread thanks. I need one

[@carlostrujillo1950]

@@HVACTechTipsI’m watching your vd, where are you located if doesn’t bother you.

[@shaunwagner6229]

im having issues now where ive found a bad 2 stage gas valve, got a replacement and now the replacement isnt working. reading no resistance on the coil but everything else is right. no problems anywhere else in the system but for some reason this ones got me REALLY doubting myself.

[@conspiraciesexposed7760]

I’d like to know how to diagnose this ^

[@patrickjordan8373]

It would be a big help to me to know what model of valve you are talking about and if you got it off the shelf or if it was shipped. The new standard of shipping is to toss a delicate piece of equipment in an oversized box with a single air pillow so that it bounces half way across the nation before it gets to you. Then when you install it you realize that you were probably better off leaving the original device in. What I would like to have seen in this video is some differential diagnosis of: Yes the inducer is running, yes the pressure switch is engaged, but what if there were intermittant problems like the inducer not being steady so that the pressure switch had minor open/closed problems that then might let the pilot light then shut it off? or the flame sensor being intermittant so that even if the mains lit that they might fail too? No bigger bugger than an intermittant fail. Lettuce know if you had any success with your valve.

[@humbertoruiz4916]

Gracias Guero

[@roqueherrera8471]

Thank U

[@MP-ju6sz]

Good video ,yet I just found out that 24v to a gas valve does not always mean the valve is bad

[@jesuscard.1675]

A good idea would be to check the inlet gas pressure, I had an experience, I checked the power from IFC and I got the 24 volts I assumed the gas valve was bad. I replaced the gas valve, and guess what? Problem still. I checked the gas inlet pressure was above 25 WC. What was the problem, outside regulator. I told the customer call the gas company to replace the regulator, after regulator was replaced, problem solved 😊. High gas inlet pressure causes the gas valve can't open.

[@jicalzad]

My HVAC tech said there was excessive moisture buildup in my gas regulator which might have froze and kept the gas from passing. He was able to get the moisture out and got my furnace up & running again. He advised me to also contact the gas company if i have another ignition lockout issue & have them look at my regulator. I'm wondering if i should just contact the gas company now anyway to have them look at it, rather than see if the problem returns.

[@l.a.m7645]

Also make sure main gas valve is open.

[@bluwng]

Mine is working but makes a rapid buzzing noise .

[@ralphriffle1126]

Wow Wow Wow! Wait you forgot one more test. If it does not open, tap on the valve several times. The reason for this is the valve might be stuck. The gas suppliers will add antifreeze to the gas from theirs storage facilities so the gas will not freeze. This can cause a little sticky build up in the valve. Once you free it your good for winter. Techs helping Techs

[@josesoto2079]

Thanks to your coment about gas valve stock after doing my test using a multimeter l did what you recomend in your suggestions and works!!!! Thanks, my friend!!!!

[@alfredo74k5blazer]

Dang it!! I need to replace my gas valve 🤨

[@juniorgarcia5344]

mince is making a static noise before it kicks on. loud noise

[@palebluedot-rc5ru]

bruh? @4:23, you just gonna ignore that monster bee chillin upturned on the burner tray?

[@jonah8641]

Looks like the gas valve been replaced before. Why not add a drip leg on the gas line and use a gas flex. Moisture may have gotten inside the gas valve. I always tell myself why did the gas valve failed.

[@waseemallinone]

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