Honeywell RTH8500 Guide D'installation page 14

Installation Guide
Alternate wiring (for heat pumps only)
If labels do not match letters on the thermostat,
check the chart at right and connect to terminal
as shown here (see notes, below).
Leave metal jumper in place, connecting
R & Rc terminals.
If your old thermostat had both V and VR
wires, stop now and contact a qualified
contractor for help.
If your old thermostat had separate O and B
wires, attach the B wire to the C terminal. If
another wire is attached to the C terminal,
stop now and contact a qualified contractor
for help.
If your old thermostat had Y1, W1 and W2
wires, stop now and contact a qualified
contractor for help.
If L terminal is used, C terminal wire must be
5
connected (contact a contractor if there is
no C wire).
If E and Aux terminals do not each have a
6 wire connected, use a small piece of wire to
connect them to each other.
2
3
3 5
5
6
4 6