Any ideas? Thermostat in house not working

[Fuzly]

I have two thermostats in the house we are moving in to. One is for the outdoor wood boiler, which goes through the forced air furnace. One is for the same furnace to use the lp gas and air conditioning. I've been running the wood all winter, but would turn it off once in a while and turn the gas up just to make sure it fired in case I had any trouble with the boiler.

Now the home is getting new drywall and the gas thermostat works, calls for heat, but the gas furnace doesn't even try to fire. The wood boiler thermostat still works fine.

The reason I mentioned the drywall is that I'm thinking the thermostat was removed from the wall about a week ago and they screwed something up, but not sure.

 

[Fifelaker]

If the blower is running check the limit switches then the gas valve. If no blower t-stat.

 

[Fuzly]

Thanks

I checked the gas valve.

No blower either. The stat says it is calling for heat, but the furnace just sits there quietly. Turning the blower switch from auto to on doesn't make the blower run either.

 

[TermiteBuffet]

IMHO if it was removed from the wall i would say they either wired it up wrong , broke a wire while installing them back or worst ran a sheetrock screw through a wire . Last guess but not likely being that part of it works , that they didn't power the unit down ,shorted out the control voltage transformer. Of course all of these are just a S.W.A.G Termite scientific wild ass guess

 

[atlarge54]

On the gas furnace where the T-stat wires connect you should have 24v AC at the red wire. Typically you can jumper the red to the white and the furnace should run in the heat mode. Depending on the furnace you may need to override a safety switch on the blower door panel.

You're on the right track with the drywall screwing up the stat wires. It's not uncommon for an old brittle T-stat wire to break, check the connections at the stat.

 

[Fuzly]

Thanks for the SWAGs:msp_biggrin:

The electrician will be back to finish up next week and I know he will help me. Just looking for things to check myself.

The thing that makes me angry is that I feel like somebody is not being honest. Poop happens, but I hope they're not trying to cover up a mistake.

 

[stihly dan]

Make sure they didn't hit the emergency switch. By the celler door.

 

[Fuzly]

On the gas furnace where the T-stat wires connect you should have 24v AC at the red wire. Typically you can jumper the red to the white and the furnace should run in the heat mode. Depending on the furnace you may need to override a safety switch on the blower door panel.

You're on the right track with the drywall screwing up the stat wires. It's not uncommon for an old brittle T-stat wire to break, check the connections at the stat.

Thanks, I think I remember the red wire hanging when I looked. I'll look again tomorrow. Also, its 5/8" out further now. Maybe they tugged a little too hard and didn't have any slack to tug?

 

[unclemoustache]

I'd certainly tell/ask the drywallers about it - tell them what's going on and see if they have anything to say. I wouldn't hold them responsible for a screw going through a wire, but if they were pulling on the thermostat hard, or something, then you might have more info to go on.