Hi,

I am changing my thermostat from an older Weathertron mechanical thermostat to a Honeywll RTH3100C Digital Thermostat. I have a Trane heat pump.

Old Wiring

R - Red
T- Brown
O- Orange
G- Green
Y- Yellow
X2 -White , jumped to W
B - Blue
W - White, jumped to X2

New Wiring Setup

Aux - White, jumped to E
E - jumped to Aux
Y - Yellow
G - Green
O - Orange
L - Not used
R - Red
B - Not used
C - Blue

I got it wired in, but nothing is working. Any ideas? All help would be greatly appreciated, as I am being reminded about every five minutes from my wife and kids that our heater is not working!

Thanks!

Did you do the setup on the honeywell stat? Did you turn the power off at the airhandler when you changed stats? May be you blew the fuse?

Something is odd. Your fist stat has both O and B used. This is very unusual for a thermostat and on few manuafactures, typically zone controls require it.

Blue (B) on the first stat, you moved to common (C). That isn't a normal connection.

There is some info here and other places. Thermostat wiring colors and furnace terminal designations repair.

Note that Trane SOMETIMES uses B for common.

I'd use B and O on the new setup and loose C. Hopefully the stat will operate without C.

Note the description for "T".

Some of the Honeywell Vision Pro stat's don't use "T" per say, but have the ability to use an outdoor sensor for the heat pump.

Also, if you didn't disconnect power when you installed the stat, the fuse on the circuit board could be blown if it has one. Typically it's an automotive style fuse.

If the fan doesn't run in Fan mode, then suspect the fuse or furnace transformer. A temporary jumper from R to G will should turn on the fan.