PDA

View Full Version : Replacing Trane Baystat240 with Honeywell RTH3100c


BHEIRD
Apr 14, 2007, 05:33 PM
I have recently acquired a residence that had a much older HA/C unit. The thermostat is a TRANE Baystat240 (3AAT80B1A1). Up till now it worked well. Recently both the heat and air were blowing at the same time. Go figure! LOL. I have recently attempted to replace the thermostat with a Honeywell RTH3100C.

The TRANE has the following wires:
R
T
O
G
Y
X2
B
W

The Honeywell has the following connectors:
E
AUX
Y
G
O
L
R
B
C (optional w/ batteries)

I have connected the Honeywell in the following fashion, but it still is not working:

TRANE Wiring = Honeywell Wiring
R = R
T = (not used)
O = O
G = G
Y = Y
X2 = E
B = C
W = Aux

The Question:
What am I doing wrong? I have tried to call Honeywell and ask for help, but I keep getting hung up on when they switch me to live assistance.
what's happening is I am getting no action at all by my system. It's the weekend now, and if I call a pro... I'll definitely pay the price. Could someone show me the proper way to wire this thermostat up? Is there a reset button on the blower and/or compressor?

Thank You ahead of time, for anyone willing to assist me.
Brent

T-Top
Apr 14, 2007, 06:44 PM
If the heat was on with the a/c with the old and new T-stat, I would say you have a stuck heat sequencer in the fan coil unit. Your wiring looks right for the T-stat change out.

JackT
Apr 14, 2007, 08:12 PM
I don't believe you can hook B on to the new C. Trane uses B to control a heating damper and C is the common side of the transformer. I believe your new thermostat requires both R & C (24 volts supply) and the old one didn't. You may be able to use the B wire by connecting it to C in the air handler section.

T-Top
Apr 14, 2007, 09:35 PM
I'm not the expert with the trane system but for what its worth I would say O - reversing valve, Y- compressor, X2- emergency heat, W- aux heat, B- common, G- blower, R- 24 volt power. Sounds like you have the older two stage heat one stage cooling mercury bulb stat.