I was trying change out a thermostat for a 200BA88 Bryant furnace -
there are 4 wires however only 3 are used: W B R. Even though the photo shows the green connected to the old stat, it connects to nothing.
the wireless smart thermostat software has become more trouble than its worth and we wanted to put on a simple 7 day programmable - no wifi
The stat I tried is the Honewell RTH7560e.
The previous stat was connected with Blue to B White to W and Red to Rh (jumpered with Rc) and it worked fine. When I connected the Honeywell Blue to o/b White to W and Red to R, the valves opened and the burners ran constantly, (even though the temperature was not low enough to turn heat on) and it didn't shut off until I turned the breaker off.
Tracing the wires to the R182c relay and the furnace controller the white wire goes to the fan limit switch then to the W on the relay and the red and blue go to the R and B on the relay.
I have attached some photos
Is this a compatibility issue?
thanks for your help...
The contol and limit switch
The new mounting system
this is the stat we want to replace