I want to replace a Robert Shaw 9420 thermostat with a Honeywell RTH7600D
7-day programmable thermostat. The package says it is heat pump compatible.

The wiring on the current (old) thermostat is this per the Rober Shaw manual:
Blue C=24 VAC, Transformer Common Side
Pink R= 24 VAC, Return
Yellow Y1= Compressor Relay (Stage 1)
Red/Reddish Brown E= Emergency Heating Circuit
White W2= 2nd Stage Heating Control
Green G= Fan Control Relay
Orange O= Reversing Valve (Cool Active)

The problem is this - installation booklet states that if your old thermostat has
Y1, W1 AND W2 wires, stop now and contact a qualified contractor for help.


I have Y1 and W2 wires. Should I get a qualified contractor?

Their diagram then goes on to show the Y1 connected to the Y terminal & W2 wire connecting to the AUX terminal in the thermostat. Do I connect my Y1 to the Y terminal and my W2 to the AUX terminal? All the other wires seem to match up easily. Aside from the warning in the instructions, I think I could accomplish this. However, could I be missing something that warrants a professional installation? Your advice as to whether if I can complete the wiring myself is truly appreciated.

Here are the available terminals in the new Honeywell RTH7600D thermostat:

C
G
Y
O/B
RC (jumpered to R)
R (jumpered to RC)
AUX
E
L

The instructions diagram for heat pump read:

RC terminal (jumpered to R) = RC or R wire
R terminal (jumpered to RC) = R or V or VR wire
O/B terminal = O or H or B wire
Y terminal = Y or Y1 or M wire
G terminal = G or F wire
C terminal = C or X or B wire
L terminal = L or F wire
E terminal = E or X or X2 wire
AUX terminal = AUX or W or W1 or W2 wire

 

Rc & R = red
C = blue
Y = yellow
E = brown
Aux = white
G = green
O/B = orange

option 170 = 7
190 = 0