Honeywell RTH8500D Owner's Manual page 17

Step 7. Connect Wires to New Wallplate (Cont)
7. Compare letter designations on your old and new thermostats.
Use the information below if you are wiring a CONVENTIONAL
System. Use the information on page 20 if you are wiring a Heat
Pump System.
CONVENTIONAL
letter designations
on the new thermostat
1
RC
1
R
W
Y
G
C
Y2
W2
Do not connect more than one wire to each terminal. Be sure
to read the notes referenced in the numbered triangles
above. These numbered notes appear on the next page.
Possible letter
designations on
the labeled wires
or R
or RH, 4, V
or W1, H
or Y1, M
or F
or C1, X, B
17
2
2
3 4
M22208
69-1725-1