How to Diagnose a Bad Furnace Gas Valve (10 Things To Check in 2021)

[@foxfamilyheatingandaircond4696]

If you want to learn how to Troubleshoot a furnace gas valve this video can give you some great information. Please comment below and let us have some of your expertise!

[@seatime674]

Fan motor running, no heat, the igniter is lighting the blue flame and then it's switching off every 3 seconds then clicking back on again cycling, not sure what this is...

[@UniversalStand]

@@seatime674 Was it the flame sensor?

[@1985kenworth1]

Thanks ..i will tell you this ..i moved the plug slightly to the right and it has been working for the past 3 weeks keeping the house warm starting and stopping as it should .I have carbon monoxide detectors on every floor of the house as well as some First alert little ones above several vents where the air is coming out to make sure .But just from that slight push on the plug that gives it power and its working .Does that mean its just a loose connection at the plug or should i still replace it ?

[@JohnnyRay920]

The entire sequence happens as it should up until the gas is supposed to ignite. I can hear the valve click, but no flame. I got someone from the gas company to come out and check to make sure I'm getting gas to the unit at the correct pressure. That's all good. So maybe something inside the valve is stuck? or maybe something is clogged?

[@teegees]

This video was very helpful and I feel like the solution is in there somewhere, so thank you. Interestingly, my furnace cycle clears all the stages that you mentioned. Except now the flames drop out after a few minutes, and only room temperature air gets blown through the air ducts. I cleaned the burners and even replaced the flame sensor rod, and that didn’t fix the issue. Pretty stumped now but I have a gut feeling that the solution is somewhere in this video.

[@delvindoodles2182]

It says a lot about you, your business and your family that you make such a detailed video covering all of this. Despite that it could even take away business from you. It is very much appreciated. While a simple thanks is all I can offer, I hope you know that you're truly blessing others with knowledge and power. Thank you again.

[@waynevaughn3107]

Thank you ! This was so helpful! I was able to pinpoint my gas valve issue. Turns out it was just some corrosion on the wire terminals but it was the accurate instructions that led me to it ! Thank you!🙏🏾

[@abelmebratu]

I had success by using a heat gun to blow hot air at the burner area while the igniter was glowing. After this initial assistance, the furnace continued to successfully ignite itself. I believe the problem was caused by frozen igniter parts. A self-feeding problem due to the furnace not running for days leading to the furnace parts becoming too cold than normal. The draft inducer motor was broken and it took a couple of days to find the part and replace it. I run into the ignition issue after replacing the motor. You should be able to use a hair dryer if you don't have a heat gun. I believe using a space heater or similar options to bring the furnace closet/area to room temperature could work. Please remember to practice safety and not rely too much on comments like mine.

[@watermanone7567]

Great video again. When I serviced some commercial HVAC in New England I would find fire dampers doors closed due to the link failing and also found internal duct insulation would fall off plugging the coils or bends in the ducts. Thanks

[@jodyhoffman1405]

Good information on gas valves, I won't replace it myself but i can at least inform the repairman what the problem is. I lost my best friend in 1974 when the house blew up from home repairs on a furnace

[@leeb.7188]

This video is about the furnace starting, but what about the end of the cycle, when it shuts off? I’m looking at a mid-80s Carrier that starts and runs fine, but then when it shuts off, you hear a small “boom” and it starts for a few seconds, then shuts off with another “boom”, then re-starts again. It does that 5-6 times, which each brief start and run getting shorter and shorter until it finally stops completely. I was looking at videos trying to determine the cause; my guess is that the gas valve isn’t completely closing so it keeps re-igniting. Anyway, an end of sequence video would be great! Everyone talks about getting them running, but not how they’re supposed to shut-down properly. Thanks!

[@mattmidili4350]

Just dealt with this last week. Luckily it was my own. Came home from work and noticed the house was about 10 degrees setpoint. Reset the furnace and everything operated as expected. Came home the next day, house was cold again, started looking into it deeper, call for heat, inducer on, HSI glows but no ignition. Take the leads off of the GV and cycle again have 24V from board to GV, so started to look further into the GV but everything checked out. What I did was hooked up the GV leads to a contractor and then cycled the furnace and it pulled in the contactor after the HSI started to glow. Also I used a totally separate transformer plugged into a different power supply and put the secondary on the GV and fed it constant 24V, cycled the furnace again and it had ignition. After some deep troubleshooting it turns out the solder points where the wire harness connects to the board were weak. Put my meter to ohms with the board out of the furnace and measured with one lead where the harness connects (with the harness) of

[@saintsamaritan]

Wow

[@nunyabusiness863]

Can't thank you enough for this. Clear, thorough, and timeless info. Told me what to look for and the safety. Thanks!

[@foxfamilyheatingandaircond4696]

Awesome!

[@gimenovax1]

I called a professional furnace man when I was having trouble and he changed the gas valve . I started having the same trouble a while later and this time I did it myself and found the gas orifice to the nossel pointing at the ignitor was plugged. I had just thrown 500 dollars into the toilet and still had to do it myself.

[@strongspear4988]

Plugged with what? And you were charged $500 to replace a gas valve? Seems like an overcharge.

[@gimenovax1]

@@strongspear4988 It was probably plugged with rust from the steel gas line, and most of the charges were travel and labour, I live a long ways from town.

[@venM9]

Its not an overcharge. Some gas valves are over 400 dollars just the part.

[@Doing_it_right_the_first_time]

If he replaced the valve and it was not the problem, then you would’ve had the same issue pretty much immediately after the tech left because it wasn’t remedied so since you say that it took a while for another situation to arise, it probably was what I call a dual or combination problem where it was probably two different things and you tackled the second thing. The tech did not go far enough to check other things as they thought it was the only problem was the gas valve.When I’ve done a repair, I will usually wait right there after it has gone through several cycles to make sure it is running properly while I’m checking other things, like pressures and connections and what not. Edward H. - “Integrity, Plumbing, Septic, Heating, and Drain“ out of the Clinton, CT area. “Doing the job right for the first time for 34 years!“

[@julianbaca2719]

​@@strongspear4988Professional furnace guy wanted $1500 to replace the bad gas valve on my furnace..

[@ginginthing]

Thx so much for this video. You just fixed my furnace. Bad pressure valve. It was getting 15 volts on start up until it kicked into 27 volts and I could feel a small click but no gas entered the nozzles. Could not find one new. Bought one on EBay for $28 used w/ free returns.

[@billgatewood9578]

Great video. One of the best explained sequence of operation I’ve seen.

[@foxfamilyheatingandaircond4696]

Sweeeet. Thanks

[@dillonlexington]

I heard you mention the return duct, but don't forget to check the vent going outside, birds nest, wasp nests etc build up in there as well and block the airflow. But this might be a topic of another video, if so, my apologies.

[@AmarBasu]

This video saved me $800!! Thanks so much.

[@foxfamilyheatingandaircond4696]

Awesome. Glad to help

[@mattmidili4350]

and the other lead on the direct backside of the board going from point to point and found one point giving off crazy readings while the others were 0.1 or 0.2 ohms. This was a tricky one with it intermittently working. I was almost dead set on changing the valve but I changed the board and has been working fine since. Sorry didn’t mean for this to be 2 comments. I hit send before I was completely finished typing

[@72bigmixx]

I had an HVAC Tech come out here today because I had delayed ignition sometimes...Burners are clean,he ran some tests and ended up saying I had a bad board because the gas valve is coming on basically at the same time as the HSI...No delay. The HSI is not getting a chance to fully warm up and by the time it does there is already too much gas in the heat exchanger and get that boom sometimes. Have you ever heard of this?

[@danielcollins9549]

I have replaced the main board and the pressure valve in the heat strip of my old Goettl HVAC system. The sequence of events you describe in your excellent video works...after I cleaned the ground connections. I now have heat! However, I still have a question: shouldn't the inducer motor stop after the system is up and running? In this roof mounted system, I still feel a healthy stream of hot air to the outside after several minutes of running.

[@knodg1]

No the Inducer should stay on till the end of the heat cycle.

[@budcmour]

Thank you for this video. It was very informative. My furnace was converted from lp to natural gas a couple years ago. In the spring, when the furnace is no longer used, I will smell gas coming from the furnace and have to shut off the gas coming to it. You mentioned a spring in the gas valve and proper tension. If my technician didn't replace the spring during the conversion, would this cause a gas leak coming from the gas valve? I mentioned the problem to him later, and he said we may need to replace the gas valve. Your thoughts please.

[@alienvu9]

This is a very good video to give you an overall knowledge of a gas furnace. I learnt a lot from this video. Thank you!

[@PBS-nm1uu]

this is a great video. please do sequence of operatiion, thanks

[@jonesy_7073]

This is a huge help. I'm getting 26v to the gas valve. I put my meter on the leads to the gas valve and it read OL when on the ohm setting. If I watched and understand the video correctly, this means I should replace the gas valve, is that correct?

[@Islamisthecultofsin]

It means that it's time to call a service tech as you can't buy a gas valve unless you're certified.

[@jonesy_7073]

@@Islamisthecultofsin actually I was able to buy one from Amazon that was an OEM Part from a distributor. Got it install and it worked immediately.

[@Islamisthecultofsin]

@@jonesy_7073 Cool. The local distributers will only sell them to licensed gas techs.

[@russelljohnson3800]

Man your a good teacher, I wanna work for you.

[@dougselin5920]

Excellent video - thanks for posting it. Can you comment on what might cause a gas valve to emit a constant tone while the gas is flowing through it? My furnace starts and runs properly but there is a tone (about 1000 Hz) that is heard and appears to be coming from inside the gas valve. I put a nut driver against the valve body when it was operating and put the other end to my ear to try to isolate where the noise is coming from. Any cause for concern?

[@itsTy21215]

I bought a 2023 Jayco 2 days ago and I test fired the furnace and literally within 20 seconds I smelled propane/exhaust then the propane alarm went off. I don’t think that is normal. Advice would be awesome. I plan on taking it back to the dealer to have them fix it but I just got it literally 2 days ago And I just want to use it. The dealer is almost 2 hours away.

[@shredfreak93]

Good video! The issue I am having is that the fan and inducer will turn on, the igniter will heat up, then I’ll hear the click of the gas valve, but no gas comes out although I have propane in the tank. Any tips or advice would be a great help, thank you!

[@brandyloch]

Dropping a common possibly

[@etlawson6939]

Call a technician because you did not understand what he explained.

[@dawnrobbins5877]

I have an old Day And Night furnace that started leaking gas from the pilot knob. The knob can no longer be moved by hand. My question is how can I find the correct replacement valve on an (apparently) outdated system? The original valve is from an 80U-19A furnace which was used in multiple brand names. Everyone wants to sell me a new furnace without trying to replace the valve first. Any advice would be greatly appreciated as I don't have the money for a new furnace!

[@joentg1390]

You talked about the evap being clogged causing the High limit to over heat I have seen a lot of very clogged air filters causing the same issues

[@foxfamilyheatingandaircond4696]

Very true. Good point!

[@eloy09]

Thanks man! Makes me a better hvac tech

[@johncalvey96]

Just what I needed exactly!!!and rt to the point. Awesome video saved me a ton. Thank you !

[@ckuiper7332]

excellent. Very thorough - yet not boring.

[@ocsantiago747]

You said the gas valve will shut off if the gas pressure is not there. Question for you bud: so we turned off the main gas line what happens to the furnace.we are in the middle of the summer do we need to turn it on or what do we do . We don't whether to leave it alone till the winter or turn it on now. Please advice

[@TM-jx5vp]

Great video. Any suggestions on Error Code 1 on a York where the Inducer turns on for a second and then shuts off? This keeps repeating over and over until you turn off the heater on the thermostat. I see 124 volts at the inducer for the split second that it turns on and then voltage drops, following the inducer shutting off. While the problem occurs the board flashes code 1. I'll be checking voltage at the gas valve next.

[@foxfamilyheatingandaircond4696]

The error code legend should be on the inside of one of the panels on the front of the furnace. Assuming it hasn't worn off 😁

[@carlosmster7637]

If not you can look for the manual online which will show you what your error code is. Look up the model number and type manual, it should likely pop up. It also sounds like you "might" have a problem with your pressure switch. So checking for 24 v through them, in and out would be something to begin with too, and see whats the issue from the error code. 11:00

[@squidusn71]

I didn't hear the click sound of the valve at 4:02. I checked the voltage and got 28 volt when activated by the mother board. I tapped it several times as well lol. I changed the valve and so far so good.

[@philkuusisto1558]

I once had water hanging up in the exhaust vent due a wrong slope in the tube, air would not pass through and my furnace would shut off before long. Put proper slope in the pipe so moisture would drain out. All is good now.

[@kirstenboucher8296]

Thanks for the interesting video. I think I have a problem: my gas sniffer is on pretty high alert in the upper levels of my house (winter in Canada). I have checked all the gas lines inside the furnace with the gas sniffer (the connections are OK), BUT the sniffer goes on very high alert when I approach the gas manifold (when the furnace is off). Is this normal that some gas escapes the gas valve when the furnace is off? Further, the furnace is three years old, and under warranty, so I had a technician come out yesterday and he laughed off the gas sniffer (he wouldn't use those things). He did the bubble test on the gas lines, and of course they were OK. He pronounced the furnace in working order. What shall I do next? (I purchased the gas sniffer a week ago because I occasionally get a whiff of gas when no appliances are starting up. I do not have a gas stove.)

[@peternone6273]

c I too would question the gas sniffer, I.E. where did you buy it and how sensitive/responsive is it, professional grade or dyi etc. However, the fact you are smelling gas via your nose I would advise you to call in another company, sometimes leaks are intermittent. Have the technician pressurize the lines to your house to 80psi and then use soap detector. Betcha they will find the leak.

[@TheGoldenHillFarm]

Having an issue with my Conquest 80 Natural Gas Furnace. My issue is that not all the burners are igniting sometimes, all of the orifices are clean on the nozzles and channels in between each burner are clean. It always lights the burner at the heating element but sometimes it takes two tries to light all the burners and will work fine for a few cycles and then do it again. I'm thinking the gas valve is starting to go bad or not enough pressure to the nozzles. I would appreciate your expertise on this issue. Thanks

[@1tayborn]

I have an old temp star furnace that is not lighting at all. All the videos show newer furnaces. I’m not sure if it’s the igniter or gas. It does not turn red at all

[@thecloudicave3307]

Sounds like a bad igniter, they are pretty cheap. If you have a hot surface igniter and it’s not glowing then it’s burnt out and needs a new one. When you put the new one in don’t touch the part with your bare fingers it’ll burn the igniter out bc of the oils on your hands

[@onlyme8870]

If the pilot and thermocouple have been replaced and still not able to light the pilot next is the a sticking valve? Tappan furnace. Manual light pilot wires all checked and nothing broken or disconnected and have continuity. I clean the furnace as well. But worked fine until the gas company shut it off for road work new gas line run to the houses on our street. And they said the blew the lines. But something doesnt add up and the servixe provider said he couldn't relight the pilot. Now left the issue with me to figure out. If the gas man couldn't.

[@DucNguyen-ww5xc]

Thanks for great video. I have a very interesting situation which i don't know the root cause. There is 24v going into the gas valve and heat is running fine. Certainly there is no voltage to the gas valve. I unplug the wires plug from the circuit board and plug it back and this time 24v are there for gas valve to turn on. If you know what is the problem, please let me know. Thanks for the help.

[@mikeesquivel4131]

Thank you for sharing your priceless knowledge!

[@theotherside7634]

Great video for this amateur , thank you. Roof mount (3ton?) HVAC I do have a question. When the leads to the gas valve energizes, are both of them energized to 24 volts or just one? On my start sequence, everything goes exactly as you described . 1. power to control board 2. Thermostat signals heat 3. Inducer comes on 4. presser switch activates, proves the inducer came on and is working properly 5. Ignite start snapping an arc to light the LP. Then nothing,. LP doe not come through the burners and light. On the gas value (Honeywell VR8205M 2401) leads, only one of the two wires get voltage, could that be a problem?

[@Jack51971]

I am having a similar problem at times. The burners will not ignite. It tries 3 times as the piece glows red. No ignition. However, I never hear the click when this happens. 4 times the last month. Most time it works. Technician yesterday $129 was not much help. Just wanted to sell me new stuff. Then they try to tell you it will cost $1000 for a new gas valve or motherboard. If I want to replace a bad part should that be my decision? See what agas valve costs online? With labor $1000? Rip off. 😮. Just like car mechanics! Rip people off!😡 Old furnace and ac rotting in a land fill too!

[@theotherside7634]

@@Jack51971 On mine I ended up replacing the (Honeywell VR8205M 2401) with a compatible replacement regulator, then after adjusting the LP pressure, it fired right up.. Had to call a HVAC part distributer for a compatible regulator, since mine was discontinued. BTW, they told me which one to buy but wouldn't sell it to me since I wasn't a contractor. Got from Amazon. Thanks to this video's checklist, I didn't waste money on unneeded parts.

[@therivereddy4408]

I have a Honeywell gas valve with an igniter assembly. The only error I get is max igniter trial fail. I took the burners out and scrubbed with a wire brush. New air filter. Poked a small wire in all the inlets including the assembly. My understanding of the sequence may be off. I pulled the igniter/flame rod out and polished the heat rod with some steel wool. I even swapped out the Q3400A1024 with a Slurk 24V universal igniter kit. Same results. I don’t hear the gas valve click, but inducer comes on, igniter glows, flame at the assembly, but not across the burners. Igniter turns off, flame turns the rod red, igniter comes on again, flame stops and then shuts down. Then I get my code. I replaced the assembly thinking maybe that’s the reason it’s not releasing gas to the burners. I’m going to clean out the A coil tomorrow and see if that helps, but I’m feeling like it’s more than that. Does this sound like a bad gas valve? I guess I was thinking the initial flame would register and then open gas to the burner inlets and kick on the blower.

[@tedpearson00]

Care should be taken when cleaning the flame rod. scrubbing with abrasives like steel wool can remove the metal coating and it will not sense correctly. Some say rubbing with paper and cleaning with acetate (fingernail polish remover) is preferred.

[@rhondawestaway626]

My furnace runs after 2nd attempt and it runs great. Was told it was a gas valve. Will the furnace run if the gas valve is bad? I have a mobile home furnace.

[@Seabass1206]

check your air proving for the inducer motor

[@howimade3309]

what happens if the ignitor kicks on glowing for 5 secs and turns off, no sound of gas this cycles 2 times and it turns off? ty

[@strongspear4988]

IMO - - Probably a sticky Gas Valve.

[@JohnAbrahamCA]

Some furnaces especially Carrier family has the main blower running first before the draft inducer run

[@dbingamon]

I might have a gas valve problem. It's Williams Forsaire Counter Flow about 5 years old, electronic ignition, direct vented, very simple design, has a mushroom inlet/exit on the outside of the house. Sometimes the regulator starts making a noise like it's going on and off. The flame actually starts but it looks like it's having difficulty when this occurs. I'm thinking either the valve is stuck or the flame sensor (which I think is a bulb with capillary tube type) is not getting hot enough and putting it in a perpetual start/stop state when thermostat is active. There is no sophisticated computer control on this, no impeller motor, pretty basic.

[@davidhaim89]

About 20 years ago, I successfully diagnosed a problem that is not mentioned in the video. My Montgomery Wards gas dryer (manufacured by Norge) had a resistor mounted on the gas valve that went bad. During startup, full voltage was normally applied to the solenoid in the gas valve, to enable opening. After flame detection, voltage was normally switched to a parallel circuit, that included a voltage drop across the resistor, which kept the valve open without burning out the solenoid. When my resistor went bad, the valve would shut off when the voltage was switched to the resistor's circuit. The problem was solved, at low cost, by replacing the resistor.

[@johngraves2968]

If a blower has a PSC motor, just for fun, check the blower motor capacitor, also check air vents at the motor and clean. this may cause the high limit to trip \ lack of cool air.

[@foxfamilyheatingandaircond4696]

Good stuff John. Thx!

[@Resist4]

My pilot lights for a bit then goes out and the igniter keeps trying to light it, but the pilot keeps going out. The burners never light. Is the issue the 3 wire pilot assembly or the gas valve?

[@FishOnIsMyHandle]

Is it okay to shut off the blue gas valve inside the Lennox Pulse G14 and not shut off the old style tapered valve in the line? We aren't going to use the Lennox anymore, planning to replace it. (I don't want to create a leak in that old tapered valve by messing with it.)

[@petesingh292]

Great presentation Graig keep them coming

[@d.j.robinson9424]

Definitely check the filter, and no squirrels in the vent pipe.

[@edaltounian7118]

My inducer is shutting off after 30 seconds (spins just fine and I've check the vacuum switch as well). The ignitor coil isn't lighting up and I've checked that as well. Flame sensor is brand new, but I can't even get to that point. No clicking on the gas valve. I'm beginning to wonder if the main circuit board has died again, but last time it just stopped working entirely. Any thoughts on this odd issue? It also runs the blower motor after a minute and leaves it on as if it's heating.

[@Vote4Trump2MAGA]

Check the sensor by taking something metal and connected to wires together like I did with mine, and see if it works. If so then replace the sensor with a new one.

[@Vote4Trump2MAGA]

This man really knows his stuff and helped me not to do a couple things that would be wrong thank you for your advice. 👍

[@edaltounian7118]

I figured it out. Bad switch above the inducer. @@Vote4Trump2MAGA

[@rodgermiller8980]

So theres a few things for you to check,on the burner box theres little switches with a reset button on them,those are called roll out switches,push the center button in and see if it clicks,there could be more than one,so look carefully,2nd,theres a high limit switch on the back wall of your furnace as your looking at the furnace,that switch will make the blower run if its tripped,you can tap on it with a screw driver to see if it resets itself,if not it needs replaced,but that switch is for if your blower motor stops working and builds up to much heat in the heat exchanger,check those parts and see if those are your problem

[@rodgermiller8980]

And check your filter,could be tripping the switch too if filter is dirty

[@angelasanchez4042]

I turned my heater on after being gone for four days and we had a really bad blizzard. Very cold here power was out for two days while I was gone. Turned it on last night the house reeked of gas, so strong. I had a headache within 20 minutes. Power company said the blower is blowing the flame out because the valve isn’t closing. Is that fixable?

[@Lags-zl3wy]

Yes call an HVAC tech. That's dangerous.

[@gregoryadamson2436]

Thank you tips, but my problem is as follows. The furnace cycles first time with no issues, but shuts off before reaching temp. A few minutes later it relights but now this is where my problem is. The flame lites runs for a minute or less and poof goes out. A few seconds later it relites and poof goes out this happens several times till it times out. Checked the roll out sensor the flame sensor and the limit switch. Both at the sensor and at the control board. All had voltage and never varied or went to 0 volts. But checking the gas valve for voltage (24 volts) it would drop to zero flame out, 24 volts flame on, back to zero ect. ect. What would or could cause this occur? I replaced the board with new but it still happens. Please advise

[@metou3072]

That seems like a pressure switch issue... I had a brand new furnace I installed with the same issue... What happened was the vacuum pressure that closes the pressure switch slowly lost the pressure which releases the pressure switch... This will happen after about 30 sec to a min... Then shut the gas off .. after 3 times it should not let it happen anymore and lockout... It could be a clogged vent... A monometer needs to be put on the pressure switch make sure it's shutting down at the correct value that is under what value is on the part... Usually a code will be given by blinking lights... Take off the furnace doors and tape the door switch down and turn on... Let the fault happen and look on the back of the furnace door for the code it gives and it will point you in the right direction

[@boundless8288]

Although seems like common sense , are the vents even open , seen that , no air flow heater will over heat

[@holtrussell]

Secondary heat exchanger can be full of debris causing poor airflow and the furnace to overheat.

[@heatncool]

Whats the process to clean that

[@Jungcheese1080]

So if I'm not getting any voltage to the gas valve, is that a definite board replacement?

[@CharlesAusterberry]

Having issues with Amana furnace today - Honeywell VR9205Q1010 valve was not activating. thought it was the control board so i replaced it. Still not working. Here what i know now. If i unplug the valve and measure between Common and Low I get 26 volts for 2-3 sec( which i should) but if I plug it in and check C & L the voltage drops to .8 Volts for 2-3 sec. , not enough to activate valve , not sure why. If i use the 24 volts from the transformer to test valve by going to C & L i can get the solenoid to "click" . Its like the broad cant supply enough current but its a new board. Any ideas? or have you seen this before?

[@angelgarcia2522]

Very well explained!

[@Me-mr9lx]

If I smell propane coming out the air inlet (yes the inlet) to the combustion chamber when the unit is not running, is it possible the gas valve is leaking by? Is there a way to check?

[@foxfamilyheatingandaircond4696]

Any time you smell gas, you need to call the utility that provides that gas and even 911. It's not something you want to be wrong in guessing whether its okay or not. Let them use their meters and tell you what to do next.

[@watermanone7567]

Great series, thanks

[@justdissin7340]

I got a 36 yr split system how can i check for 24volts going to gas valve on furnace? Top terminals on gas valve are numbered 1,2,3,4,5 . Theres a yellow & white wire at gas valve going to the sec 1 & sec 3 on main board

[@jasonclark5034]

My furnace worked by me tapping the gas valve assembly with the wrench last winter. Now it doesn't. I can hear the solenoid click but no gas comes through and the system shuts down. Sometimes it fires up on it's own with no tapping.

[@waterfuel]

What about a furnace gas leak in the cellar? Propane gas detector is mounted near floor and near furnace. Opposite a couple yards away there is an electric 200v dryer. The under carriage of dryer has red hot nichrome wire coil open heating element, when dryer is ON. This must be a common issue?

[@ralphwhitaker8761]

What does the pressure switch does according to heating?

[@binhdo6094]

you are a good teacher! thanks.

[@TNHVACLIFE]

Thanks for the video

[@stevenvachon9745]

My furnace runs fine most of the time but occasionally it runs for a long time (sometimes an hour) before it ignites. The tech said it was the gas valve and replaced it with a new generic one as the original was too old and not available. It didn't work at all and though it was faulty (occasionally happens with new values?) so replaced it with another (different brand I believe). Still didn't work so put back the original. They seem pretty experienced techs but said they could not figure it out. Thankfully they did not charge me anything. It just started getting less reliable so I am getting concerned. Any ideas anyone?

[@stephenhuggins1388]

I have a LP carrier gas furnace, took wires off of the valve and only had 20-21 volts wouldn’t ignite, used jumpers and took them from the thermostat terminals on the board to the gas valve connection spades on the valve and heard the valve open, does that sound like a bad board? A resistor not bleeding down properly?

[@stephenhuggins1388]

Also did fine the black plastic part where the two wires plug into on the valve was very loose, only weird thing is is that the furnace is only 3 months old

[@venM9]

Welcome to the era of cutbacks and cheap overseas parts. I am replacing a gas valve second time in a 2 year old install.

[@titanmongoloid8164]

​@@stephenhuggins1388If the wires were very loose, it may have a bad connection. I would pinch the connections with some pliers to make them snug.

[@stephenhuggins1388]

Ended up being the control Board

[@vk71000]

Thanks for this video, it really helped.👍

[@GM-wf6el]

Hello. Great video. I live in an apartment and the gas furnace stops working during a power outage. Can I connect a vehicle battery or some other power source to the furnace so that it will run during power outage? Thanks

[@ralphriffle1126]

I think on important step was not mentioned. After the gas valve opens and the main burners are lit and the flame is verified the limit switch must get hot and close, ( bimetal ) then the fan will come on. This ensures the firebox is hot so cold air will not blow into the house

[@johntimlin6664]

I recently had a furnace (carrier) for a no heat. When I engaged the heat the system came on but shut down as quickly as it ignited. Checked flame rod , press. Switch,gas valve : replaced gas valve but still same problem. Ended up being the pc.board. manager said to bypass valve to check operation. Then I would have known it was the board

[@joeharvie8362]

Great advice!!

[@bigjonbird1]

What's it mean when your furnace will not turn on in the morning when it's cooler but after 5 failed ignites , a reset, then it will start normal. Or later on in the day or works fine.... Massive because it's warmer?

[@SignorNessuno65]

Same kinda thing happening to mine. Slight smell of gas also.

[@jorgegonzales6697]

It depends and could be a few things. Do you have loose connections at your gas valve? How cold is it when it won't start? Does the inducer start? Does the hot surface ignitor glow bright orange?

[@bigjonbird1]

@@jorgegonzales6697 blower fan comes on. Ignitor glows bright. Gas valve goes from 12volts to 67 mv . 3 attempts to start then it goes into lock out mode. I reset then it fails one more attempt and starts on 5th try. Only thing I can think of is the ignitor is not getting hot enough.... Or gas valve sticks when cold. Thank you for replying. I might have to just call in expert which I'm trying to avoid.

[@jorgegonzales6697]

@@bigjonbird1 it sounds like you have a meter and know how to use it! That's awesome! That's about 20% of an hvac tech job 🤗. Disconnect the ignitor plug before turning it on. Measure the ohms of the ignitor plug while it's cold. Most measure around 50 but you may need to Google the model# on the attached tag or the adapter itself. If it says Kyocera, though it's probably 50. Then with it still unplugged at the connection, turn on the furnace and measure the volts coming to the ignitor plug from the board while it's trying to start. My best guess, though is it sounds like your gas valve may be failing. Ok I'll leave you to it. I just enjoy my job a lot

[@bigjonbird1]

@@jorgegonzales6697 that's so helpful. Thank you. I appreciate your time and response. Have a great Christmas!

[@zipperdingo6385]

All your videos are excellent man👌

[@twitteryindiana]

I havnt worked on a furnace in several years. Mainly just heat pumps where I live. I had a gas valve today that would not put any gas through it at all followed all the sequence of operations, igniter came on but no gas. Then finally out of nowhere after resetting unit several times it just came on and I’m getting gas. So I left, then an hour later it kicked back off and won’t come back on. It was off for several hours when I first got there. Any thoughts? Thanks!

[@Progress24.7]

Change the valve. Did you find a solution?

[@squidusn71]

You basically found the problem like what the guy said on this video.

[@kylebuehlman4207]

I’m having troubles with my roll out switch on my furnace keeps opening if it gets hot by the switch but I’m not getting any flame roll out and the pressure switch is doing everything it’s supposed to it’s just the roll out switch

[@djkaneck1]

Still nobody has answered my question...what happens when the board sends only 2.4 volt to the gas valve?

[@foxfamilyheatingandaircond4696]

If you're not getting 24v to the valve it's bad. You could test it by jumping 24 volts to the gas valve from the transformer or somewhere else that has 24 volts. If you hear the gas valve click open you have a bad board.

[@djkaneck1]

I replace the IFC board and still 2.4 volts. I replace all the sensors and switches including roll out and limit switches. Still only 2.4 volts plus checked continuity to all wires. Nobody ever mentions my situation

[@foxfamilyheatingandaircond4696]

@@djkaneck1 I wish I was there, I could help you get it going. It may just be time to have a tech come out and diagnose. I wish I could've helped more over messaging like this.

[@cyrilgantzer3383]

@@djkaneck1 were you able to fix it? seems to be the same for me, 2.0V to the gas valve no matter what.

[@cyrilgantzer3383]

@@djkaneck1 is it possible that you were looking at DC voltage and not AC voltage? That's what I was doing wrong...

[@saintsamaritan]

Nicely technical, but pictures or diagrams inserted instead of watching & trying to follow Mr. Fox would be very helpful.

[@richardli8348]

Excellent Video!

[@foxfamilyheatingandaircond4696]

Thx!

[@mysplashtopaccount5038]

Awesome video.

[@Steve-og3cr]

Should it be a constant 24vac? Or just a "blip"??

[@foxfamilyheatingandaircond4696]

Constant 24v

[@Steve-og3cr]

@@foxfamilyheatingandaircond4696 I suppose I see a blip since the flame sensor will not have flame. Need to check while it's running. My gas gets cut mid cycle. That's if the valve even comes on. Limit/pressure switch are good, replaced flame sensor. I have a new main board and gas valve on the way. I'm not convinced which one it is yet. Ugh.

[@HonestyHVAC]

@@Steve-og3cr it’s your gas valve👍 replaced them several times in that same situation and it is the solution

[@Steve-og3cr]

@@HonestyHVAC bizarrely... It's been working perfectly the last 3 days...that's good and bad lol. I keep waiting for it to lock out to do more checks. Each time it "failed" it left the blower on. I powered off, got draft fan/ignitor glow, then only 12v at the valve leads off the valve. I power cycled a few times and it hit 24 - 27V. Plugged wires back on valve and it fired up. I know SOMETHING is dying. I have a new board and valve on standby as well as a limit switch for kicks. I have "beaten" the valve and it has kicked on from lockout. I have wiggled limit switch wires and it's done the same. Even cleaning old flame sensor (replaced now) seemed to change it's behavior. So unfortunately it's still not nailed down what the issue is. I see slight green corrosion on the board on an area or two. It's got to be the board or gas valve. I jumped the limit switch and it wouldn't fire. I'll wait and see when it finally dies lol.

[@HonestyHVAC]

@@Steve-og3cr yeah it can be frustrating, I’ve seen several times this season a gas valve with intermittent solenoid problems, stuttering to open or failing to open then working fine for multiple heat cycles. I would bet money Replacing the gas valve will fix it, as for your voltage problems I would make sure all 24v connections are good, don’t see intermittent transformer problems so possibly your 12v reading was a bad connection as well.

[@larryl43]

THANK YOU

[@gabinoflores8267]

Great video buddy thanks

[@alico1x2]

Its reading 15v when is idle than 25 volt when i turn it on but gas valve wont click nor gas will come out. Shouldn"t i be reading 0 volt when its not on ? is it bad valve or something else? Thanks in advance.

[@Omfg_Its_Santos]

Did you fix your problem?

[@frankie385]

I was just told by the tech that i need a new gas valve. The estimate came to around $600ish is this right? I did a quick search for the part and it was around $150. Sure labor, troubleshooting etc. but $600? also, I am an engineer and run a Lab, and am very very proficient with tools and safety protocols....believe me when i say...it took every ounce of will power to not do this myself, gas is nothing to fuck around with, and although i can afford the $600, I dont want to end up blowing up my house. so pay the $600. What is the life span of a gas valve under normal working conditions? North Texas.

[@foxfamilyheatingandaircond4696]

Yeah we are at $775 for a universal single stage gas valve.

[@frankie385]

@@foxfamilyheatingandaircond4696 thanks for the reply it makes feel at ease. Your experience, what is the life span on this valves under normal conditions?

[@joseaguilar402]

Don't be tight

[@KLHDRW]

My Honeywell vr8204h1147 buzzes when the thermostat calls for heat on my utica steam furnace. The furnace does light but the valve continues to buzz for a time.. perhaps when the call is satisfied. It seems to do this for the first few days the furnace gets turned on in the fall then the furnace works like normal with no buzzing sound for the rest of the winter.. I have found conflicting reasons why this happens. Is it bad, just dirty, or something else?

[@dbingamon]

That sounds a lot like my furnace. Only I have it off for now until it's fixed.

[@tedpearson00]

I am no expert but have been around these units a while. The buzzing coming from your valve indicates 24V is going to the unit but the valve is not opening. You can check the 24V with a meter. If this is truly the case and your valve is sticking closed until it has been operating a while, the valve can also STICK OPEN unexpectedly! :O You may be operating on dangerous lines here and should change valve immediately.

[@andrewthacker114]

Good clip thanks

[@The.Lone.Wolf.]

Lovin these vids

[@spellmadam2947]

Thanks

[@shambl2]

Does a bad gas valve cause a bad smell to come through your vent, that smell like a strong smell that smells like how a has stove smell? I have natural gas but when my heat is about to turn off I smell a strong smell that smells like that smell when turning on a gas stove. I had the fire dept to come out and the gas company and there's no gas leak at all.

[@JohnAbrahamCA]

Could be heat exchanger cracked

[@jagrench62]

This must be one of the fancy new fangled space furnaces. Mine is nothing like this.

[@brianboitschenko2456]

That's funny lmao rite dam alien's.lmfao

[@roberts1159]

Gas furnaces like this have been in existence about 20 years.

[@jagrench62]

@@roberts1159 I was wondering , mine is older than that.

[@Wheresmybong6]

I find a lot of limits tripping due to lack of airflow. Dirty filter

[@mr.fixdaplate]

legend

[@terrythomas790]

My York furnace is 4 yrs old. Just recently it would work fine. Then out of nowhere it would blow cold air, I see a steady single red diagnostic flash, meaning heat called for , but no flame sensed . I cleaned the flame sensor, which really wasnt dirty,but a bitch to get out and in due to a very tight area. Ran fine a few cycles and repeats the problem. I shut of power and turn back on and it works a day or two, then back to square one. Im thinking a sticking valve. I always see the ignitor glowing properly. Any ideas? I have a 10 year parts warranty, but Im thinking the service call would be twice the $150 cost of the part. Im thinking buying the part and saving money, which actually makes the warranty useless. Thanks

[@danielbinnings3924]

Same issue here. Please let us know if you figure it out.

[@Noname23489]

same issue here, everything runs fine for me, just noticed this slow red single flashing light coming from the furnace cabinet, did you ever get yours fixed?

[@Noname23489]

same issue here, everything runs fine for me, just noticed this slow red single flashing light coming from the furnace cabinet, did you ever get yours fixed?@@danielbinnings3924

[@terrythomas790]

@@Noname23489 What I did was to tap the valve when the ignitor glowed, and was due to open, and presto, it ignited. And after that it worked properly. My thoughts were that after not running due to summer, it kind of stuck from non use. This summer, I might just once in awhile turn on the furnace a couple times to maybe keep it from sticking. Just an idea. Never had to repair anything.

[@winkhvac62]

Good video!

[@foxfamilyheatingandaircond4696]

Thanks brother

[@batata754]

Wuuaaaooo...eres grande...thanks 👍😎👍

[@zamilahmed736]

Love it. Nice video.