Answer My Searches

I replaced my old Trane thermostat with a programmable one today on my multi-stage heat pump. Here are some tips:

The wires wrapped around the screws on the old thermostat, on the new one they go under the tiny metal plates behind the screws. I had to cut the exposed part of the wires back so they just fit under the plates without any exposed wire showing.

The new thermostat will say it’s not for a 120/240 line voltage system. Don’t worry, if you have a BAYSTAT240A you don’t have that. I guess those line voltage systems are actually pretty rare in general?

Wiring tips:

The new Lux thermostat will bring a little paper that shows wiring cross references for various thermostat models you are replacing. I followed the one that said Trane and everything worked. Specifically the connections were:

reading old to new (Trane to Lux):
X2 (black wire) to E
G to G
Y to Y
R to R
O to O
W to W2
B don’t use
F don’t use (I didn’t have this one though)
T (tan wire) don’t use

This was a helpful page and the here is the manufacturer’s page which might help.

Disclaimer: I don’t know what I’m doing, this worked for me but no guarantees it will work for you. Caveat lector!