Troubleshooting Gas Furnace Cutting Off Randomly!

[@Growzarktrail]

Jeff, thank you for your videos. I am commercial refrigeration transitioning into more heating. Your videos have been a great help!

[@JeffsHVACAdventures]

Good to hear!

[@kat2641]

Modern technology at its best 😂 them intermittent are the worst to find.. great troubleshooting!!!

[@JeffsHVACAdventures]

Thanks.

[@TomLawson05]

Great job Jeff diagnosing problem and fix that return was weird thanks for the video

[@JeffsHVACAdventures]

Sure was! I found out from the owner that they did that with the return years ago in an attempt to reduce noise 🤷‍♂️. Thanks Tom.

[@Balticblue93]

@@JeffsHVACAdventures You have to love homeowners. They are suffocating and system at the expensive of sound, brilliant plan! It should have increased face velocity actually making more noise through a small space. But who knows.

[@izzymoney85]

Great work had the same problem today but mine was more of a pain in the ash but at the end of the day i got her done 😅

[@JeffsHVACAdventures]

Good stuff brother.

[@bobparrott8130]

Good job Jeff !!!

[@woodystokes1543]

Nice work 😊as always 😊

[@zekenzy6486]

Great video. Thank you for sharing

[@MaintenanceMan00]

Great video. New subscriber!

[@carlbass4449]

They were trying to reduce the blower motor noise inside the living space... that's my guess.

[@MariosACandRefrigeration]

That blower motor sounds like bad bearings,and the return duct seems small,the duct board is because it is too noisy,thanks for sharing.sometimes you have to sell them a new one.

[@JeffsHVACAdventures]

Spot on about the return noise! Owner told me that when I went back.

[@ATAKace1]

These are always my least favorite to diagnose. End up having to go through everything

[@CubbyTech]

Noisy blower motor! I'll bet that long return is blocked for 2 reasons: Like you said a 2nd return, as well as not sucking in a bunch of cold air when the A/C is on.

[@markcotter2355]

Did the board fix it? I was thinking thermostat issue?

[@JeffsHVACAdventures]

Yes. I started thinking that at first too but I babysat my meter waiting for the W call to drop and when the burners cut.. the W call remained.

[@Wolfhound.]

blower motor sounds like its not long for this world

[@HVACR559]

IMO, the two DMM's just confuses the diagnosis. Even if one DMM displayed before the other it may have to do with its sample rate and how long it takes to display that on the screen. Especially with different brands of DMM's. I would start at the secondary of the transformer set the DMM to min, that way you can see any dropouts even if it's too fast too shut it down or for the DMM to display. Pluss you don't have to stare at the DMM. Then move the DMM after the board and down the line of safeties until you see the problem. Low voltage intermittent shorts can be found by setting it to MAX with the amp clamp. Move the clamp down the line right to the bad component. Be sure yo use a popper on the secondary of the transformer to protect it. They don't take 20 + amps for very long before they let the smoke out.

[@realSamAndrew]

Aren't amps exactly the same throughout the circuit? How does moving the amp clamp tell you anything?

[@HVACR559]

@@realSamAndrew Yes if we were in a series circuit. We're not dealing with a series circut. The amperage will change down the line because the opposite side of each component has a parallel connection to common.

[@HVACR559]

@@realSamAndrew This is not a violation of Kirchhoff's Law.

[@HVACR559]

Even if you started with a series circuit that developed a rub-out, the series circut has now become a parallel circut. It will have high current flow to common at the rub-out. That high current won't be on the other side of the rub-out.

[@justinpisarski412]

I think they blocked it off because of noise