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View Full Version : Change old thermosat to new one


pm4phs
Jan 19, 2009, 09:07 PM
When taking out a T-90 general control thermosat I did not label the wires. Trying to install a new honeywell, its not working. I can't get the old wires in the right order.

Blue goes to...
Red goes to...
Green goes to...
White goes to...

New sat has Rh,Rc,G,W

pm4phs
Jan 19, 2009, 09:10 PM
I forgot y on new sat

hvac1000
Jan 19, 2009, 09:54 PM
It is a shame you did not write down which color wire went where on the old thermostat. Without that knowledge wiring the new thermostat can be guess work and that is not good. I suggest you go to the furnace and see where the wires for the thermostat are hooked to. List the terminals G,W.Y.R, etc with the color of wire attached to that terminal. Then post that info back here so we can figure it out and be accurate about it so no damage happens to your new thermostat or equipment.