Solve Dozens of Furnace Problems With This Process

Dive into the logic of an HVAC Service Tech to diagnose dozens of common furnace problems.
00:00 Introduction
00:16 Confirm Power, Fuel, Call for heat
00:28 Checking Thermostat
00:49 Confirming Power
02:03 Testing Door Switch
02:23 Confirming Fuel
02:51 Sequence
03:03 Checking 3 or 5 amp fuse
03:35 Securing Door Switch
03:46 Repowering Furnace / Time Delays
04:31 Inducer Motor / Limit Switch Problems
06:24 Inducer Motor / Thermostat Problems
07:17 Inducer Motor / Control Board Problems
07:36 Inducer Motor / Bad Motor / Jammed Cage
08:19 Pressure Switch Problems / Testing
09:31 Pressure Switch / Flue Pipe Problems
09:59 Pressure Switch / Blocked Tubing
10:27 Hot Surface Ignitor / Testing
11:40 Gas Valve / Testing / Burner Issues
12:48 Flame Sensor Problems
13:57 Blower Motor

[@jrh86]

Thanks JM this is a perfect tutorial/ refresher and is one of the best on the Internet today, thank you for your time and knowledge in its production 💯💯💯👍👍👍 its just what I was looking for 👍

[@JerseyMikeHVAC]

Thank you, brother. I appreciate that.

[@u2tipsy]

It's always a good thing when you accidentally find your mentor on KZbin who happens to live 3000 miles away. Your content, knowledge, demeanor, and delivery is 🔥!

[@JerseyMikeHVAC]

Thank you!

[@franknielsen3562]

This is one of the best video’s for an old electrician, that never worked on many furnaces. Eliminate all before calling for help. Thank You

[@JerseyMikeHVAC]

You're welcome.

[@giiodude]

I’m the kind of guy that asks, “but what if this doesn’t work and why not?” You answered every question I had in my head while watching.

[@JerseyMikeHVAC]

Perfect!

[@texsradio3628]

Mike, I like how you always explain things simple n detail. Thnks

[@JerseyMikeHVAC]

Very welcome

[@betorenteria7768]

As a new tech, this video is extremely informative. Much obliged, sir!

[@JerseyMikeHVAC]

Glad it was helpful!

[@gabrielsamy007]

Hey Jersey Mike, I recently subscribed to your channel and I want want to thank you for your videos. You are very good at explaining things and I am learning a lot as I review your videos. Thank you!

[@JerseyMikeHVAC]

Thanks and welcome aboard! If you ever have any questions just reach out.

[@kobie4238]

Great video, i wish i had this when I first started.

[@Fordo11789]

Great video! Currently out for a bit due to bday celebrations, can’t wait to get back into the field and get after it especially w this!

[@SeamusDaly-oc3yw]

Thanks JM for sharing your knowledge , much appreciated

[@JerseyMikeHVAC]

Any time

[@jnm001]

One on the best videos I have ever seen - thank you!!!

[@JerseyMikeHVAC]

You're welcome

[@andresortiz1373]

I just started to watch your KZbin videos, wow where you been at all this time?

[@williamspiller5032]

EXCELLENT TUTORIAL! YOU ARE GOOD. YOUR SPEECH, FLOW AND CLARITY WAS ON POINT.

[@JerseyMikeHVAC]

Thanks

[@miguelrojas3394]

Awesome explanation Mike thanks.👌🙏

[@JerseyMikeHVAC]

Very welcome

[@richlikeg3722]

Good timing, at least I know what the heck I’m looking at.

[@saltrue1555]

Thank you very much this is very instructive .

[@JerseyMikeHVAC]

You're welcome.

[@charleswilson6872]

I’m an hvac tech and I love all your videos Ive seen so far, do you have a tutorial like this video for electric heat sir??

[@JerseyMikeHVAC]

Thank you. I do have a heat strip video here: kzbin.info/www/bejne/m2HRoGeJmqmCnbc

[@jeffreyhill3960]

Excellent tutorial. Good teacher….

[@cheponite2461]

Thank you for making this video 👍 I'm about to go back to hvac school soon

[@JerseyMikeHVAC]

Good luck!

[@abrahamlizardo86]

Awesome basics video. Thank you.

[@user-pw1mc5gw2m]

Thanks Jersey

[@JerseyMikeHVAC]

No problem.

[@stevencossaboon3237]

Nice video Mike. Thank you for the knowledge.

[@JerseyMikeHVAC]

You're welcome

[@mikec5513]

Excellent Video. Nice Job.

[@howtodoitdude1662]

Thanks for sharing! Very useful information!

[@JerseyMikeHVAC]

My pleasure!

[@bjohn4793]

Dude you cooking thanks guy

[@JerseyMikeHVAC]

Any time

[@teklesenbetgebreamlak7365]

Great video Mike really appreciate your time to put all furnace sequence operations

[@JerseyMikeHVAC]

My pleasure.

[@JohnDoe-ej1lw]

As always good learning content in your vids.. Thank you for taking the time to put this great wealth of knowledge together 👍

[@JerseyMikeHVAC]

My pleasure!

[@Gabriel-vz7ml]

Thank you.

[@JerseyMikeHVAC]

You're welcome!

[@diverm2371]

Well done. Thanks

[@JerseyMikeHVAC]

Thank you too!

[@chesstime356]

Very nice video

[@boobachelli]

Your videos are a wealth of knowledge! Always look forward to the next one!!! Troubleshooting ones are great!!

[@JerseyMikeHVAC]

Thanks! Going to try to start moving more towards including diagnostics moving forward.

[@cenricocustoms6489]

Wow…excellent teacher, very valuable info thank you so much… finally someone who really explains clearly 💪👍🔥🔥🔥 Do you have one for heat pumps as detailed as this video?

[@JerseyMikeHVAC]

Thank you. I have 2 vids going over HP wiring and sequences. Not exactly a diagnostics video, but will certainly help in diagnostics if you know the content. kzbin.info/www/bejne/lWSbpWCIhc53ras kzbin.info/www/bejne/nXOtq4mMbMugla8

[@CMN843HVAC]

Great video 👍👍👍

[@JerseyMikeHVAC]

Thank you

[@johngallati8164]

VERY CLEAR...AWESOME VIDEO...

[@JerseyMikeHVAC]

Thank you

[@wim0104]

this is awesome, thank you.

[@JerseyMikeHVAC]

You're very welcome!

[@deanmartin1966]

Nice job. Good video man

[@JerseyMikeHVAC]

Thank you

[@elgkas9928]

Another great tutorial. You are saving people money and more importantly, you are educating us.

[@JerseyMikeHVAC]

Glad to help.

[@jimtwisted1984]

Oh yea a like and subscribe for you. I like your style man.

[@JerseyMikeHVAC]

Thank you!

[@WilliamNicholsLC]

I graduated because of you..😂😂 thanks

[@JerseyMikeHVAC]

So I get a cut of all future commissions, right? Lol. Jk. Nice job.

[@WilliamNicholsLC]

@JerseyMikeHVAC as soon as I receive my mechanical license, we can discuss!!

[@jdogar1]

Thanks Mike great video. Hi Mike I cane across a furnace today at customers garage. This furnace had no control board at all. It had a limit switch. And gas valve had 4 electrical terminals attached to it. Do you Recall any furnace like that.

[@JerseyMikeHVAC]

Yeah I've seen it before. The TH/TR terminal is just a jumper for power from the transformer, through the limit switch and to the thermostat. The TH/TR is not internally wired in the gas valve, so technically you could bypass it and just go from the transformer straight to the limit switch then to the thermostat and it'll still work. The TH terminal gets the 24v signal from the thermostat on a call for heat (R to W at the stat). TR is the common going back to the transformer common to complete the circuit. It's still a 2 wire activated gas valve like many others.

[@markcotter2355]

thanks for the good sandwiches.

[@JerseyMikeHVAC]

You want fries with that? 😁

[@antonlavey5540]

Just turn thermostat to fan on to see if you have power.

[@JerseyMikeHVAC]

That's another way to confirm power, but that only works when the fan actually comes on. If it doesn't, you can think you don't have power when you do and it doesn't tell you if it's a high voltage or low voltage problem, a thermostat or furnace problem, a breaker or fuse problem, a capacitor problem, etc.

[@realSamAndrew]

Mike, is the pressure switch being monitored the whole time the furnace is running or only at the initial check when the inducer first turns on? In other words, is it possible for the vacuum check to pass, and then 5 minutes in the pressure switch can briefly open, would that stop the cycle after the furnace has already started?

[@JerseyMikeHVAC]

Yeah I've seen that happen for quite a few different reasons, from a bad pressure switch on a new unit, to flue obstructions, to bad pitch on 90% flue pipe and even temperature drops outdoors creating denser air and starving the unit. Normally I don't monitor the whole time unless I suspect issues with it. I'll hook up a manometer and keep an eye on it.

[@realSamAndrew]

@@JerseyMikeHVAC I was asking if the BOARD monitors the pressure switch constantly. If the ptessure switch opens at any time, with the furnace running 2 minutes or 47 minutes, will the system shut off instantly? I always assumed the vacuum check was only one time at the beginning to prove the draft for startup.

[@JerseyMikeHVAC]

@@realSamAndrew I don't believe the board monitors the pressure switch directly, but it does monitor the burner circuit and the switch is part of that.

[@Sc19869]

I thought if the switch is closed you should be reading 0 volts and when open it should be 24 v

[@my-yt-inputs2580]

Coincidentally yesterday one of my units decide to crap the bed. Severe cold snap with snow/ice soon to happen. Package unit(Trane) so harder to work on it in the outside bad weather. My unit was coming on but the registers inside didn't seem to be getting very warm. After running for quite a while the blower would shut down but my thermostat(Nest) was still indicating a Heat Call(glowing orange) I went outside and pulled the access panel. What I notice happening is the Inducer motor comes on and shortly after the burners(only 2 of them) light. Somewhere in that sequence the blower motor starts. The burners remain lit for 10-15 seconds. Maybe too long for a flame sensor issue? I might pull it and clean again. The cycles again and again until some point the system turns off. I have Green and Red LEDs on the board. Only Green light is indicating but according to diagram operation is normal. Red LED does not light indicating any other issue. I pulled the flame sensor and cleaned it with emery cloth and reinstalled it but didn't make a difference in operation. So I'm kinda stuck getting anyone here to work on it due to outside weather. My son is in the business but he lives a few miles out of town and roads bad.

[@my-yt-inputs2580]

@@JerseyMikeHVAC 2008

[@realSamAndrew]

Sounds like a rollout switch or high limit tripping.

[@realSamAndrew]

​@my-yt-inputs2580 you can test the flame sensor by connecting a simple rigid copper wire inline with the flame circuit.

[@my-yt-inputs2580]

@@realSamAndrew Those are my next 2 choices.

[@realSamAndrew]

@@my-yt-inputs2580 would you please come back and tell us what it was when you get it fixed?

[@kellismith4329]

Click, whirr, buzz, woosh

[@JerseyMikeHVAC]

Hopefully no boom.