Honeywell RTH8500 Series User Manual page 10

Installing your thermostat
Alternate wiring (heat pump system only)
Use this if your wire labels don't match the terminal labels.
You must have
Note:
a C wire or equivalent.
See page 6.
Alternate wiring key (heat pump system only)
1
Leave metal jumper between R and RC terminals in place.
2 If your old thermostat had both V and VR wires, check wifithermostat.com for help.
If your old thermostat had separate O and B wires, attach the B wire to the C terminal. If
3
another wire is attached to the C terminal, check wifithermostat.com for help. Attach the O wire
to the O/B terminal. Set System Function 0190 to 0 (see page 22).
If your old thermostat had an O wire and not a B wire, attach the O wire to the O/B terminal.
4
If your old thermostat had separate Y1, W1 and W2 wires, check wifithermostat.com for help.
This is the system monitor. If the monitor finds a problem, you will see a red light in the upper
5
right corner of the thermostat (shines through the cover).
If old thermostat has separate wires on AUX and E, place both wires into the E/AUX terminal. If
6
old thermostat has wire on AUX with a jumper to E, place wire on E/AUX terminal. No jumper is
required.
7
Do not use K terminal. For future use.
33-00133ES—01
L
5
E/AUX
6
K
7
8
HEAT PUMP
Metal Jumper
RC
Y2
R
O
AUX
Y
G
C
RC
1
R
2
O/B
3
Y 4
G
C 3
MCR33530A