19 replies to this topic

[Hozer]

Checked the thermostat by jumpering the red and white wires and get nothing, air conditioning works compressor and blower come on when you turn the temperature down, blower works in the fan on position, pilot light stays on so thermalcouple should be good, 24 volts coming from transformer.

Burners will not ignite in the heat setting when temperature is turned up and no noise when the temperature is turned up and held.

what could be wrong?

[RegUS_PatOff]

is there 24v AC between Red and White ?
Furnace model number ?

[Hozer]

I don't know, will check. Model Number RCDA-075A-AR

What if there isn't 24v between red and white, what then

[Dan Webster]

If you ain't gettin 24 volts to the gas valve solenoid she won't fire off. Might be a tripped limit somewhere. Post some photos of the pilot the gas valve and the furnace. Lookin up HVAC sucks.

[Hozer]

How do you fix a tripped limit

The file on my pic is too large to post, can I email to you?

[Dan Webster]

I don't know about email. I had a guy send me a zip file once and spent the rest of the night fixin that.

Does it have a control boaard
does it have a pilot light or a ignitor?

[Hozer]

I don't think it has a control board, It has a pilot light not an ignitor

[RegUS_PatOff]

is there 24v AC between Red and White ?

[Hozer]

the photo is a jpg not a zip file

[Dan Webster]

In that case send it to: sublimemasterjw@rocketmail.com

Or post it to my facebook wall

Edited by applianceman18007260692, 03 November 2011 - 07:34 PM.

[Hozer]

Red and white wires do not have any voltage

[Hozer]

any updates, Red and White wires do not have any voltage between them

[kdog]

If the 24 volts is not present, you have a failed transformer or one of the rollout thermosats has been tripped as applianceman had mentioned

[Shootist]

Nothing wrong with the transformer if the A/C runs. On a pilot furnace you're either getting 24v to the 2 wires plugged onto the gas valve or you're not. If you're getting 24v and the valve isn't opening then the valve is bad. If you're not getting 24v and you have red and white jumpered at the thermostat then trace the 2 small wires back from the valve. One will go back to common, the other will go back throught the fan limit and sometimes a little roll-out sensor (or 2) above the burners. Some older horizontal furnaces have an additional limit in the blower compartment as well.

[Samurai Appliance Repair Man]

Posting the photo that Hozer emailed me:

Click for large view - Uploaded with Skitch

[jb8103]

What a piece of junk.

There's the transformer right there on the left, hanging on the J-box. (Probably stapled.) Check for 24 VAC there.

Better yet, don't bother. Get a new Goodman in there.

Anyway, if you have 24 VAC at the transformer but not at the thermostat then you have a disconnect somewhere between the two devices. Do what Shootist advised, and also keep in mind that a mouse will chew through a t-wire in a heartbeat. I'd bet money on that, and I'd also bet money that old clunker does not have a terminal strip, so if you do have 24 VAC at the transformer your next move is to figure out how to jump the red and white in that spaghetti wiring in the furnace. Get that, and it should fire up, which if it doesn't, you got more than one problem.

[Dan Webster]

I see the limit above the gas valve to the left. You need to check that limit. If it is open you will have no heat. That limit would pop out due to rusted burners or partially blocked vent. As you can see in the photo the black wire on the gas valve goes to that limit then to the fan/limit then over to the transformer. So the pilot can be lit and working but no 24 volts can get to the valve if that limit is tripped.

Edited by applianceman18007260692, 13 January 2012 - 12:17 PM.

[jb8103]

You're right about that, of course, but, checking back, Hozer says he's got 24 at the transformer but not at the t-stat, so there's his problem. That was all back in November though, so I think our man is long gone, froze to death, and we're just talking to each other.

[Dan Webster]

Hopefully he ran some more wire from tstat to furnace or installed a new tstat. Wouldn't want him to freeze to death.

[Shootist]

Another perfect example of why folks should stop back by and let us know if we gave good advice or not. Otherwise we just have to believe that we're always brilliant.