Figure 8
Connections for heat pump thermostat
About Heat Pump Systems
Heat Pump (2 Stage Heat / 1 Stage Cool)
1) Terminal 5 (O/B) controls the reversing valve for the heat pump.
The Reversing Valve setting is set to Cool by default. If the heat pump requires the
reversing valve to be energized for heating, configure “Reversing Valve” to “Heat”
under “HVAC Settings” (Setup and Configuration).
2) With a call for Stage 2 on a two speed heat pump, both compressor outputs Y1 and
Y2 are energized. When 2 stages of cooling and 2 stages of heating are configured
for a heat pump, Stage 2 is considered high speed on the heat pump and not auxiliary
heat. If auxiliary heat (or emergency heat) in needed, configure 3 stages of heating
under “HVAC Settings”.
3) The Emergency Heat Relay (E Terminal) and outdoor thermostats (usually
accessories to a heat pump), are not used. The RC500-2EW automatically controls
auxiliary heat efficiently. If the heat pump is equipped with an outdoor thermostat, it
should be removed from the auxiliary heat circuit.
1 2 3 4 5 6 7 8
(RC)
(AUX)
(G)
(Y1)
(O/B)
(C)
(G2)
HVAC SYSTEMS
24VAC “HOT”
THERMOSTAT
24VAC Common
24VAC
CONTROL
TRANSFORMER
Reversing Valve
Compressor
Fan
Auxiliary Heat
Fan Stage 2
11
CONFIGURATION
• The “System Type” must be set to “Heat Pump” under “HVAC Settings”.