Honeywell RTH8500D - Page 19

19 69-1725-1
Step 7. Connect Wires to New Wallplate (Cont)
8. Compare letter designations on your old and new thermostats.
Use the information below if you are wiring a HEAT PUMP
System.
Be sure to read the note referenced in the numbered
triangles above. These numbered notes appear on
the next page.
L
C
Y
R
RC
VR or V or
M22210
2
3
3
1
G
AUX
E
R
O
Y
G
C
L
E
W2
O/B
4
H or B,
Y1 or M or
F or
X or B,
F or
X2 or X,
AUX, W1, W or
HEAT PUMP letter
designations on the
new thermostat
Possible letter
designations on
the labeled wires