When measuring voltage at a valve, I disconnect the wires and put the leads on the wires. If the valve coil is shorted, it will pull the voltage down and you could be fooled into thinking you have a bad board.
I’ve found it best to test both with wires on valve and off because sometimes if the board is bad it will give 24 volts out but when u put it on the valve it will disappear I usually jump out the gas valve straight to 24 V while using a manometer and that will tell if valve is definitely bad
@russelldenton8753 The reason for removing the leads when ohming out a device, such as contacts on a control board, is to ensure you get an accurate and reliable measurement. If the leads are not disconnected, the meter might pick up resistance from parallel paths in the circuit, meaning it could measure additional components or wiring that are still connected. This will result in an inaccurate reading that doesn’t reflect the true resistance of the device you’re testing. Additionally, backfeeding can occur when there is residual voltage or current present in the circuit. This can interfere with the measurement and may even damage the meter if it’s not designed to handle it. For example, when you ohm out contacts on a control board without disconnecting the leads, the reading is often not zero. This happens because the meter is measuring resistance not just through the contacts but also through other parts of the circuit, such as resistors or capacitors that may still be connected. Disconnecting the leads ensures the device is isolated.
I have had that problem. if you took the wires off the gas valve and tested for you 24v you would see it doesn't drop out. when you test for 24v with the wires on it it will drop out.
Man i love watching his videos he breaks everything down and shows how he fix everything which is awesome most other youtubers don't show ever step this guy really know how to make a video brother keep doing what u doing man u rock
Glad they'll be nice and warm. Tis chilly outside. We're kinda cold here in Minnesota -1 heading for -30 wind chill. So having the furnaces checked out in fall is a must do! Great job! And please keep the videos coming! You've helped this homeowner save some $ especially your AC postings re: capacitors replacement and coil cleaning. Merry Christmas from Minnesota!
I knew as soon as the video started what the problem was. Why? Because I had the same problem. I was checking for 24 V while the leads were connected to the bad gas valve. For some reason that bad coil wouldn’t let the voltage go through. I would get 9 V at one point. Then I’d get 0 V. I learned to test for 24 V without the leads connected. Good video man. By the way, the green ground wire that was loose on the inducer motor we usually attached to the extra ground terminals on the gas valve. I really don’t think it matters to be honest.
Channel lock tight tgen make sure it's pointed where you want to to and that's it . The new valves are crap and easy to crack. It'll never leak I promise
i'm an old,, very old combustion tech, and i enjoy trying to beat you to the problem. in this case i was heading to the igniter not proving. good job! proving me wrong! plus,, dude,, why don't you use aluminum pipe wrenches!
Had the same problem on the same furnace replaced the board twice before figuring out it was the valve. Mine would would fire every time for a second then drop out like a flame sensor. Once I took the wires off the valve to test 24v power stayed there longer . That won't ever get me again
Hi Mr. mechanic I don’t know why you wouldn’t check with the wires off of the valve just to see if you could get established 24 V if you couldn’t get 24 V with the valve out of the circuit then you know for sure they’re over is the problem that have anything to do with any safeties or anything doing with the machine? That’s what I would check first then I have a note to go from there over for sure, but I think something is shorting after your your 24 causing it not to show up anyway that’s my little talk for today. This is Fred from Tallahassee.
Watching you cranking down them pipes on that value i was waiting for that value to crack there only made of pot metal and i never use pipe dope on values, only Teflon tape to try to make sure pipe dope doesn't get in value
@@bobboscarato1313Chineseium is derived from stolen research work at MIT by a Chinese National on an expired student visa. The alloy was developed by Professor Adolph Schnitzengruben and his graduate students 11 years ago. 5 years of research and development gone.
Hi Curtis when you trying to ohm out the gas valve that won't give much clue because the gas valve they used DC voltage not AC voltage. When you ohm it out you actually ohm out the dc rectified circuit in there.
Just so you know the gas line should have a sediment trap (drip leg ) before the gas valve & the flex connector should not enter cabinet of the furnace. NFPA 54 requirements but it is what it is & you got them going 👍.
That's a counterflow Rheem furnace on its side, there is a low temp limit in the blower compartment that breaks power only to the gas valve and when it's failing you will get intermittent shut downs and power loss to the gas valve. It may be a call back.
I learned from my senior guy not to measure at the valve but disconnect the wires one confirm 24 from the board if not 24 bad board if there is 24 volts take a contactor and see if it pulls the contactor in if it closes it bad valve.
Great work chasing down diagnose of bad valve. The only other thing I would have checked is incoming gas pressure , and no pressure switch restrictions.
Could have saved yourself a lot of guesswork and doubting yourself if you would read the amp draw also on your low voltage…some control boards will reset ( just like thermostats) when they are pulling a higher than normal amp draw…
I find it best to jump gas valve out to 24v while using a manometer any time I think it might be a bad gas valve or board it takes all the guess work out. u could have probably diagnosed this unit in 10 minutes by doing so. But keep up the good work brother I love the videos
Those intermittent shorts can be a head scratcher, I had a contactor coil with the same issue I replaced the control board and still had the same trouble , I ohm out the coil contactor it was up to spec but once I replaced it the system work perfectly😅
Im sure you knew this already. You just forget. All the cooling calls in the summer and rarely do gas valves fail that often. It happens brother just try to remember the next heating season or whenever you have an issue like this one again.
Having 24 volts at the valve is not conclusive! Checking the current going thru the valve however is. Checking the resistance (ohm) of the valve is not conclusive either, because there is a bridge rectifier within the circuit. The on-off switch can be faulty. They are very flimsy but easy to fix once the cover is removed.
I may be wrong but from the sequence of operation once the igniters receive the 120v from the board and gets to a certain temperature it sends voltage to the board witch then sends 24v to the gas valve 🤷♀️ but great job 👍🏽!!
![ILLSLICK X YOUNGOHM - We're The same [Official Video]](http://i.ytimg.com/vi/yUJNkobYR0E/mqdefault.jpg)
that "i think i can get one more turn on this" always gets you lol
Gas pipe does not have to be super tight
When measuring voltage at a valve, I disconnect the wires and put the leads on the wires. If the valve coil is shorted, it will pull the voltage down and you could be fooled into thinking you have a bad board.
Crap I knew someone would beat me to saying this.. 😅 I'm not a parrot! 😊
can you explain this in more detail please? I want to understand this more thoroughly.
I’ve found it best to test both with wires on valve and off because sometimes if the board is bad it will give 24 volts out but when u put it on the valve it will disappear I usually jump out the gas valve straight to 24 V while using a manometer and that will tell if valve is definitely bad
@russelldenton8753 The reason for removing the leads when ohming out a device, such as contacts on a control board, is to ensure you get an accurate and reliable measurement. If the leads are not disconnected, the meter might pick up resistance from parallel paths in the circuit, meaning it could measure additional components or wiring that are still connected. This will result in an inaccurate reading that doesn’t reflect the true resistance of the device you’re testing.
Additionally, backfeeding can occur when there is residual voltage or current present in the circuit. This can interfere with the measurement and may even damage the meter if it’s not designed to handle it.
For example, when you ohm out contacts on a control board without disconnecting the leads, the reading is often not zero. This happens because the meter is measuring resistance not just through the contacts but also through other parts of the circuit, such as resistors or capacitors that may still be connected. Disconnecting the leads ensures the device is isolated.
You were lucky that gas valve was not crack. You tightened tomuch.😊
I have had that problem. if you took the wires off the gas valve and tested for you 24v you would see it doesn't drop out. when you test for 24v with the wires on it it will drop out.
what do you mean by voltage dropping out?
Always like your videos. You always show the good and bad. It's appreciated.
Man i love watching his videos he breaks everything down and shows how he fix everything which is awesome most other youtubers don't show ever step this guy really know how to make a video brother keep doing what u doing man u rock
Good job Curtis.........
Great job Curtis, that one was a head scratcher.
Glad they'll be nice and warm. Tis chilly outside.
We're kinda cold here in Minnesota
-1 heading for -30 wind chill. So having the furnaces checked out in fall is a must do!
Great job! And please keep the videos coming! You've helped this homeowner save some $ especially your AC postings re: capacitors replacement and coil cleaning.
Merry Christmas from Minnesota!
Getting Stumped is Not in your Vocabulary. Great job, Curtis. 👍🙏
I knew as soon as the video started what the problem was. Why? Because I had the same problem. I was checking for 24 V while the leads were connected to the bad gas valve. For some reason that bad coil wouldn’t let the voltage go through. I would get 9 V at one point. Then I’d get 0 V. I learned to test for 24 V without the leads connected. Good video man. By the way, the green ground wire that was loose on the inducer motor we usually attached to the extra ground terminals on the gas valve. I really don’t think it matters to be honest.
Interesting find. Good troubleshooting skills.
I use a 24 volt contactor to check if the voltage is dropping out
Genius
That's a great idea 💡
👍
Great job Curtis thanks for the video
Excellent work curtis 👍
Thanks 👍
Had the same problem before Curtis. Great job.
Channel lock tight tgen make sure it's pointed where you want to to and that's it . The new valves are crap and easy to crack. It'll never leak I promise
Rheem mid limit in fan compartment in series with gas valve, you will get ignitor but no power to gas valve has fooled me once lol
That wasn’t the problem
Same here
I just had a similar issue today on a ducane furnace ended up being the gas valve as well unbelievable huh 😂
i'm an old,, very old combustion tech, and i enjoy trying to beat you to the problem.
in this case i was heading to the igniter not proving. good job! proving me wrong!
plus,, dude,, why don't you use aluminum pipe wrenches!
Sentimental reasons. I’ve had the same pipe wrenches for over 20 years
Had the same problem on the same furnace replaced the board twice before figuring out it was the valve. Mine would would fire every time for a second then drop out like a flame sensor. Once I took the wires off the valve to test 24v power stayed there longer . That won't ever get me again
Well until the next time when they redesign the gas valve. lol
Dang valves!
How can HVAC people make money if nothing breaks down? lol
Well done 👍
Hi Mr. mechanic I don’t know why you wouldn’t check with the wires off of the valve just to see if you could get established 24 V if you couldn’t get 24 V with the valve out of the circuit then you know for sure they’re over is the problem that have anything to do with any safeties or anything doing with the machine? That’s what I would check first then I have a note to go from there over for sure, but I think something is shorting after your your 24 causing it not to show up anyway that’s my little talk for today. This is Fred from Tallahassee.
Well done Curtis, you rectified that job nicely, and it runs well now.. BTW,, Ted has a video to view 😮 Au
Watching you cranking down them pipes on that value i was waiting for that value to crack there only made of pot metal and i never use pipe dope on values, only Teflon tape to try to make sure pipe dope doesn't get in value
That isn’t pot metal. It is pure Chineseium alloy or Mexicanium alloy.
@@bills6946 Are those Registered trade brands? lol
@@bobboscarato1313Chineseium is derived from stolen research work at MIT by a Chinese National on an expired student visa. The alloy was developed by Professor Adolph Schnitzengruben and his graduate students 11 years ago. 5 years of research and development gone.
The coil in the valve is shorted to ground causing the board to reset when 24v is applied.
Main thing is you figured it out. Nice work
Hi Curtis when you trying to ohm out the gas valve that won't give much clue because the gas valve they used DC voltage not AC voltage. When you ohm it out you actually ohm out the dc rectified circuit in there.
Wished they made it easier. Maybe a torque spec would confirming.
Just so you know the gas line should have a sediment trap (drip leg ) before the gas valve & the flex connector should not enter cabinet of the furnace. NFPA 54 requirements but it is what it is & you got them going 👍.
That's a counterflow Rheem furnace on its side, there is a low temp limit in the blower compartment that breaks power only to the gas valve and when it's failing you will get intermittent shut downs and power loss to the gas valve. It may be a call back.
I did check that.
Is that just on Rheem? Thanks.
@@bigd3104I’ve only seen those limits that kill the valve on these furnaces
@HVACGUY OK, Thanks!
I learned from my senior guy not to measure at the valve but disconnect the wires one confirm 24 from the board if not 24 bad board if there is 24 volts take a contactor and see if it pulls the contactor in if it closes it bad valve.
Great work chasing down diagnose of bad valve. The only other thing I would have checked is incoming gas pressure , and no pressure switch restrictions.
Well its working fine; there may be a few more customers wanting to get their heaters repaired as well.-
Could have saved yourself a lot of guesswork and doubting yourself if you would read the amp draw also on your low voltage…some control boards will reset ( just like thermostats) when they are pulling a higher than normal amp draw…
Check the ground on the board.
👍👍👍
There usually diodes in the valves.
Veto pro pac and m12 driver 👍
I hate those Honeywell valves they are horrible about sticking open and closed too.
I find it best to jump gas valve out to 24v while using a manometer any time I think it might be a bad gas valve or board it takes all the guess work out. u could have probably diagnosed this unit in 10 minutes by doing so. But keep up the good work brother I love the videos
I ALWAYS ISOLATE
Those intermittent shorts can be a head scratcher, I had a contactor coil with the same issue I replaced the control board and still had the same trouble , I ohm out the coil contactor it was up to spec but once I replaced it the system work perfectly😅
i remember same problem happened to the steven
Hey Curtis thanks for the video, what magnet are you using looks so handy, I could use one for the winter since we have many no heat calls
Supco furnace pro clip. Amazon sells them
@@justinrichard4190 thank you
Left a link in description
They work great I got one a month ago.
A tricky one , Most of us would have blamed the flame sensor . But it likely was sending 7 micro amps ?
Im sure you knew this already. You just forget. All the cooling calls in the summer and rarely do gas valves fail that often. It happens brother just try to remember the next heating season or whenever you have an issue like this one again.
Does sll gas valves ohms same readings? I didnt even know you could ohmed them out.
Having 24 volts at the valve is not conclusive! Checking the current going thru the valve however is. Checking the resistance (ohm) of the valve is not conclusive either, because there is a bridge rectifier within the circuit. The on-off switch can be faulty. They are very flimsy but easy to fix once the cover is removed.
How would you charge for that?
What brand is your tool bag?
Veto tech pac mc
23:15 "Veto Pro Pac"
69K and rising.
Loose wires in your molex plug?
Can’t check ohms in gas valve has a diode bridge
I may be wrong but from the sequence of operation once the igniters receive the 120v from the board and gets to a certain temperature it sends voltage to the board witch then sends 24v to the gas valve 🤷♀️ but great job 👍🏽!!
first