Forum Discussion

DonJon99's avatar
DonJon99
Explorer
Jul 19, 2016

Thermostat replace

Hello everyone! Need a little help please.
Iam trying to replace my Coleman thermostat to my roof Ac with a digital one. The Ac unit has 4 connections Y-compressor GL-low fan GH-high fan B-unknown. The wires coming out of wall where thermostat was is 4 small wires that go to Ac and two bigger wires 12v+ and 12v-
The thermostat is plain nonprogrammable digital with these hookups. B O G Y W R RC. What goes where? I was thinking:
AC UNIT.--------------THERMOSTAT
Y ----------------------Y
GH--------------------G
GL---------------------- Not using low speed right now
B.------------------------ I don't know???

POWER.-----------/---- THERMOSTAT
12+.--------------------R&RC jumper installed
12- ------------------ I don't know????

So basically I think I have it right but the 12- and the B wire. Thanks for any help!
  • Got it!!! I hooked the B on Ac unit and the 12- volt ground out of wall together to the B on thermostat to make it work. Thanks biscuit for the help.
  • Have a separate furnace with its own thermostat. Wasn't sure if I could run it off the same thermostat as the Ac unit. No the Ac unit doesn't have a heater.
    The new digital thermostat is a Honeywell RTH111
  • Your thermostat doesn't control furnace also....WHITE wire???

    Here is a Coleman to Hunter......you don't state which digital t-sat you are using???