[GrahamCowan]

Having some problems.

Background: Trane XV80 and Honeywell RTH7500D

I have 5 wires coming from the controller board on the gas furnace:

W1 (white)
R (red)
G (green)
Y (yellow) and
B/C (blue)

If it is of any help, there is a jumper on the board between W1 and W2.

According to the Honeywell instruction manual, they are now hooked up on the following:

B/C (blue wire) -> C
G (green wire) -> G
Y (yellow wire) -> Y
W1 (white wire) -> W
R (red wire) -> R

System setup 0170 is set on 1.
System setup 0180 is set on 0.
The rest are pretty much default.

No heat at all. In fact, I woke up last night to a nice 59 degrees in the house. The wife was thrilled. No fan runs, no nothing. It's like I just left it off.

So I look up the XV80 online and see it is a 2-stage furnace. So I change system setup 0170 to 8. But with only one W (W1) wire I don't really see the point, but try it anyway.

Now the fan runs, but I really can't tell if it is putting out heat. You'd think I would hear the roar of the burners, but nope, oh well.

I call Honeywell and sat on hold for about 45 minutes. The tech has me do this and that, set 0170 to 1, etc. Verifies all the wiring is correct, etc. Still nothing. So now he is convinced that it is a system problem and now the ball is in my court. How can the old Trane thermostat work perfectly and the new Honeywell not, I ask. He says he doesn't know but it is a system problem. I guess "system problem" is where they get to stop helping and disconnect.

Anyway, I hooked it up again like I had it before, set 0170 to 8, and turned the whole thing off. I will wait until the temp drops to about 65, then try and crank it up.

Meanwhile, I am all ears for help on this one. The old thermostat sucks and is unprogrammable, that's why I wanted a new one. (The tech actually asked!)

[MarkwithaK]

Could be a compatibility issue between your Trane furnace and your Honeywell stat. Trane likes you to use their equipment and theirs only. This in mind they will sometimes design a system that needs a very specific stat. Seen it too many times on their commercial equipment. Put your old stat back on and see if it the unit operates normally.

The 2 manufacturers I steer folks away from are Trane and Lennox.