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 👍
It's always a good thing when you accidentally find your mentor on RU-vid who happens to live 3000 miles away. Your content, knowledge, demeanor, and delivery is 🔥!
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!
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?
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. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_38t-RPiDwI.html ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-gBJzVV7fm_M.html
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.
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.
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?
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.
@@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.
@@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.
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.
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.
