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View Full Version : Hunter 42995B thermostat wiring for Rheem heat pump


strockenz
Nov 16, 2007, 11:06 AM
System: Rheem all electric heat pump.

Broken thermostat: Honeywell T841A1308 Heat Pump Thermostat

Replacement Thermostat: Hunter 42995B

Current Wiring:
"X" -brown wire
"B" -blue wire
"W2" -white wire
("W2" is also jumped to an "E" terminal)
"R" -red wire
"Y" -yellow wire
"G" -green wire

Terminals on the new Hunter TS:
"G"
"W"
"Y"
"Rh"
"Rc"
(by default, Rh and Rc are jumped.)

The instructions on the Hunter manual don't make it clear what I need to do. My guess is to eliminate the brown wire, connect the red wire to "Rc", the blue wire to Rh, the others to the letter corresponding to their color, and eliminate the "Rc" to "Rh" jumper. I have been given to understand, however, by looking at a websight or two, that in NO CASE should I be guessing.

Please help me. Much thanks in advance.

Oh! As to why I think my thermostat is broken: The heat comes on and stays on when I turn from "off" to "heat". There is no more automatic shutoff when the house warms up. It just gets warmer and warmer. When I pull the cover off the little mercury bubbles are tilted all the way to one side. Changing the temperature setting makes no change in the position of the bubbles. However if I take those bubbles connected to their coil and manually move them side to side, tilting the mercury back and forth, the heater goes on and off. Therefore I think there's a mechanical breakdown in the thermostat.

Thanks again for any advice.

JS

hvac1000
Nov 16, 2007, 03:56 PM
Here is a diagram for your old thermost showing where the wires went and what they were for.Transpose these over to your new thermostat areas.

http://customer.honeywell.com/techlit/pdf/69-0000s/69-1217ef.pdf

NOTE!! I believe your new Hunter stat is not for a heat pump and that could also cause you not to be able to hook it up. Save the Honeywell file because you will need it when you buy the correct thermostat.