Honeywell RTH8580WF - Page 9

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.
3. 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, check wifithermostat.com for help. Attach the O wire to
the O/B terminal. Set System Function 0190 to 0 (see page 55).
4. If your old thermostat had an O wire and not a B wire, attach the O wire to the O/B terminal.
5. If your old thermostat had separate Y1, W1 and W2 wires, check wifithermostat.com for help.
6. This is the system monitor. If the monitor finds a problem, you will see a red light in the upper
right corner of the thermostat (shines through the cover).
7. If old thermostat has separate wires on AUX and E, place both wires into the E/AUX terminal. If
old thermostat has wire on AUX with a jumper to E, place wire on E/AUX terminal. No jumper is
required.
Do not use K terminal.
8. Install battery.
Insert the coin cell battery (included), observing the correct polarity.
9. Attach thermostat to wallplate.