I have a Trane XE1000 Heat Pump which had been working fine for many years until I blew my thermostat up a little while ago. It was a Honeywell CT3611.

I am wanting to replace with a Honeywell TH8321, but in looking at the wiring diagram (http://customer.honeywell.com/techlit/pdf/69-0000s/69-1706.pdf) for single stage heat pump with aux. heat backup, they list different wire names compared to my current (but now dead) thermostat.

In looking for a new thermostat, I've found a TH8321 locally.

Can this be mapped to my wiring?

My current wires are:

G O Y W1 E W2 R C

The TH8321 has these marked terminals:

L E Aux S1 S2 RC R O/B Y G C

Thanks for any tips.

I got my system (Trane XE1000 Heat Pump with Aux. Heat) up and running with the new thermostat. While the aesthetics are much better and the programming is much easier than my old thermostat (CT3611), one thing that I noticed this AM is that this thermostat seems much more likely to kick in the Aux Heat.

I have a 2 system house with a gas furnace in the basement. I'd like the heat pump to be much less aggressive with turning on the aux heat and rely a little more on the gas furnace to help bring the temperature up in the house.

I found a setting (580 or 680) which states adjusts an "aggressiveness" factor for the aux heat but it still seems to kick on quickly.

My old thermostat had a feature called something like adaptive heat recovery which calculated how long it took to heat the house back up and adjusted itself to just turn on earlier if it takes longer to warm the house. Granted, I didn't sit around the house all day watching the thermostat to count the hours the aux heat was on or off, but it seems like it was less.

Does this new thermostat do the same thing in terms of trying to minimize aux. heat use? Is it just a matter of time before the thermostat learns my house and heating patterns? Does having the external temperature sensor help?

Thanks,
David

no your new T stat only allows two settings to use. one for slower and one for faster heat up.
If the Aux heat is kicking in you may have the heat turned down to much at night. Even though you think your saving money by turning it way down, with heat pumps your better off leaving the temp you drop only about five degrees. As the new system you have is much more efficent then what you most likely had before.
Check with Trane dealer however. I am sure they have another stat that will have that inteligent recovery you had with the old one.

does trane have a website or a specific distributor in the NYC area? thanks, blackdiamond13 @ Jemsite

[quote]My current wires are:

G fan
O reversing valve
Y call for cool
W1 call for heat
E emergency heat
W2 call for heat aux (back up heat)
R 24v supply
C common

The TH8321 has these marked terminals:

L service light, indicator light
E emergency heat
Aux back up heat (heat strips)
S1 remote sensor (some new units have an outdoor sensor(thermometer) incorporated in the circuit board)
S2 remote sensor
RC 24v supply cooling
R 24v supply heating (can be jumpered to RC)
O/B reversing valve (some energize for heat, most energize for cool)
Y call for cool
G fan control (used to turn fan on from auto)
C common

colour coding can vary, depending on the wiring used. it appears that several of the terminals on the new t-stat will not be used. swap your wiring one at a time, or mark them with a tag to ensure they are rewired like the old.