New Honeywell thermostat connected to old Climatrol heat pump
I recently bought a Honeywell thermostat RTH7600D to replace an old thermostat (containg a Mercury tube) in my condo.
Heat pump is 20+ years old Climatrol 753-2-18W-10.
The old thermostat is a Kepro 1262-1 (?) and had the following wires connected:
Green wire to G-F
Yellow wire to Y-C
Red wire to R-V
Black wire to W-H
I've followed the Honeywell instructions and connected the wires as follows:
Green to G
Yellow to Y
Red to R
Black to O/B (??)
Cooling works fine but when I turn the heating on and set the temperature to higher than room temperature it keeps on cooling - which seems to indicate that the changeover valve is not connected properly (tired both setting it to 0 and 1 in the thermostat options).