Trane gas Furnace wiring issue

Praetor · 08-12-2012, 09:20 PM

I recently bought a house with a Trane XE60 Furnance. I discovered that the furnace is not working. The Trane XE900 A/C unit on it works just fine I think there is something wrong with the wiring on the White Rodgers 36C03 valve.

What I see is that The White Wire from the TStat is not terminated near the Relay.

On the Valve the TH goes to the Load limiter then to the TCO and VSS and to the transformer where it meets another white control wire.

The TR goes straight to the transformer

The Th-TR has nothing on it.

Now, could any of this have anything to do with the Pilot not staying lit? I personally don't think so but when I replaced the TC it still did not work so I am afraid the valve is shot.

Thank you in advance.

Patrick.

Doc Holliday · 08-12-2012, 09:52 PM

So the inside and the outside unit comes on during cool and works but when put on heat you have nothing? What about fan on, anything? Can you take some pics of this wiring?

Praetor · 08-12-2012, 10:21 PM

Yes, it cools great. Here are some photos.

Valve and Limiter switch

Transformer

One side of 8 pin relay (pins from top to bottom 7,8,1,2) The white wire on pin 8 goes to the compressor.

Other side of relay (pins from top to bottom 6,5,4,3)

Sorry about the blury pic. Note the two white non-terminated wires.

Doc Holliday · 08-12-2012, 10:35 PM

You have a meter to test low voltage through that wire when on call for heat? It certainly looks like the one simply pulled from the terminal. What I'd hate to do is inform you (as soOn as I find a wiring diagram for that furnace if I can) how to wire it and then find out someone purposely disconnected it due to something like a cracked heat exchanger in the furnace which would put out carbon monoxide and could kill you in your sleep if that is the case.

When it comes to furnaces and situations such as this I'd prefer to recommend you call a tech out who can check your furnace out, make sure it's safe before it's turned back on.

That's just me. Perhaps someone else will say to simply stick that wire into it's terminal and light it up.

Praetor · 08-12-2012, 10:49 PM

So, I called for heat and it started to heat, (heat pump?) but with no furnace.

The white wire from the T-stat (3rd pic) is showing me 25vac. Only millivolts on the other white wire (4th pic).

Doc Holliday · 08-13-2012, 05:29 AM

If you have a heat pump then the outside unit would be running during a call for heat and the gas furnace would be emergency heat.

Praetor · 08-13-2012, 08:31 AM

Yeah, that's what it's doing. I think I'm going to call someone to come take a look at it.

Thanks