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Heat PumP: Rheem Two Stage Heat, One Stage Cool Thermostat Replac

Heat PumP: Rheem Two Stage Heat, One Stage Cool

Present thermostat: Rheem 41-20804-15 Present Wiring:
R = Power (transformer)
B = Changeover Valve (Heat)
E = Emergency Heat Relay
Y = Comressor Relay
W2 = Auxilary Heat Relay
G = Fan Relay
X = Power return

I want to replace the present thermostat with a Honeywell RTH7500D. I have the instruction manual but it is not specific. It would appear that the wiring would be as follows but I am not sure:

R = R/RC
B = O/B
Y = Y
G = G
X = C
L = L
E = E
W2 = Aux


Posted by geraldhumphr on

  • Bill Long Mar 11, 2014

    You are correct (R = power transformer) (B = changeover relay) (Y=Y) (G=G) (X=C Power return) (L=L) (E=E) (W2+W2)



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Bill Long

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R = R with jumper to RC hot side of transformer
B = Reversing valve
Y = Compressor relay
G =Blower
C = common on transformer (X on old t'stat)
W2 = Auxillary heat
E = Emergency heat

Posted on Mar 16, 2010

  • Paulette Riley
    Paulette Riley Mar 08, 2014

    IT has RH,RC,Y,W,G ON THE NEW Thermostat.

  • Bill Long Mar 11, 2014

    You are correct (R = power transformer) (B = changeover relay) (Y=Y) (G=G) (X=C Power return) (L=L) (E=E) (W2+W2)



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