HVAC issue, please help?!!?!?

Sorry, didn't know you had already done that.

 

Yeah the lowers don't. I think they were for sail switch option.
H stat has 2 wires: one straight to humi, the other picking up 24v on t stat wire when called for.

 

you are correct! in my opinion, i think that the humidifier is screwing everything up. meaning it is not wired right, which COULD cause your furnace to come on and off. it also sounds like the furnace is doing what the humidifier SHOULD be doing. make sense?

 

Hmmmm. Haven't made any changes in last several minutes and kicked on and ran for 3.25 minutes.

 

As far as I know it should. If it were a gas furnace it should. Does it completely shut off when you turn the thermostat to the off setting?

All my experience is with gas heat, but typically the control board in the unit is initiating and verifying a sequence of operations. If it sees a failure somewhere in that sequence it will stop and flash the diagnostic led. You should be able to look through a clear window in the door and see this. If you pull the door off again without looking for the light you will clear the fault code. So make sure you are looking for that light before pulling the door off. As others have posted there should be a list of codes somewhere inside the unit, normally on the rear of the access door. The fault code will tell you why the control board is shutting the unit down and give you a place to start troubleshooting.

 

Sort of....house at 25% and h stat set to 40% so should be calling for voltage constantly at this point.
I agree though, not able to wrap my mind around his wiring setup, with two different wires grounded to plenum.

 

No blinking though. Only the two green LEDs "ok" and "power"

 

Thanks so much for helping guys. Joey you've contributed an inordinate amount of time and I sincerely appreciate it. I'm just gonna leave humi unhooked and call the HVAC place Monday I guess. It's still gonna work acceptably just not correctly. Feel free to continue posting up ideas if you're enjoying this troubleshooting challenge and I'll follow.

 

Let us know how this turns out. I'm curious now. I have seen a couple of these hot water setups but it's been a long time now, and they were both pretty old, not as much going on inside as yours.

 

im just getting into the service side of things. been in the HVAC trade for 13 years, but only in the install side. i have along way to go and lots to learn. good luck and hope it works out for you.

and anytime i can try to help and i am not busy im glad to help!

 

x2

 

Yeah, I've had it since 2005 (Hardy wood stove) and its functioned superbly. I installed humi in 07 and worked perfectly. In 09 we added on and remodeled and upgraded AC and decided to do furnace and bigger blower and the HVAC guy reinstalled humi but it would run even when furnace blower not running. So I called different HVAC company and they sent this guy out Wednesday and I thought we were gtg. NOT!

 

When we added on in 09 I branched off the return line to boiler to feed a floor heat manifold for 2.5 bay garage, bonus room above garage, new kitchen ceramic tile (used to be old garage), and our master bath (ceramic tile). 3000 feet of 1/2" pex on 4 different t stats and 12 zones. I'd love to have the whole house heated this way and no forced air heat.

 

T stat bad. I had told the tech to check it b/c it had shorted out and I even saw him remove cover and look at it but I did not.
Duh! Obviously burnt in pic above. Gonna pu a cheap heat-only T stat tonight and see what happens.
Good ole hi tech Hg T stat!

 

Keep it simple, eh?

 

Could be a bad stat

 

Yep, working good now. Cranked it up and raised house temp by 5 degrees in no time and humidity by 2%. Woot!

 

The burnt wire in the picture is called the heat anticipator. I think it allows setting a delay between the mercury contacting and the t-stat calling for heat. I believe it stops the furnace from "hunting" if it is just on the borderline between turning off and on. I am not an HVAC guy but I worked at a heating wholesaler for many years. We would refuse warranty on thermostats with burnt anticipator because it is caused by incorrect wiring. I only mention this to suggest you double check your wiring!

 

Looks like you got it going! That is great.

 

Yeah Gary same thing my tech said. It got shorted when I was rewiring humidifier. Actually saw smoke coming from t stat but seemed to work ok for several months until recently. Just not sure why it finished going south after starting humidifier. Been such a mild winter so far, probably didn't realize wasn't working correctly.