Mode
Thermostat to Control
Board 24 VAC
Control
Control Function
Thermostat calls for 1st stage Heat
(Heat pump heating mode)
Y/Y2 & G
ON
Compressor ON, Fan ON after delays at selected Heat Pump CFM
OFF
Compressor OFF, Fan OFF after selected Heat Pump delays
Thermostat calls for 2nd stage Heat
(Electric heat)
△
W1 & W2
▼
ON
Fan ON at selected Heat CFM, 1st stage & 2nd stage of Heat ON**
OFF
1st stage & 2nd stage of Heat OFF, Fan OFF
Heat pump 2 stages, with Electric Heat
Continous Fan
G
ON
Fan ON at the selected continous fan CFM
(Fan switch ON)
OFF
Fan OFF
Thermostat calls for 1st stage Cooling
Y1 & G & O
ON
Compressor ON, Fan ON after delays at 80% of the selected Cooling
CFM
OFF
Compressor OFF, Fan OFF after selected cooling delays
Thermostat calls for 2nd stage Cooling
Y/Y2 & Y1 & G & O
ON
Compressor ON, Fan ON after delays at selected Cooling CFM
OFF
Compressor OFF, Fan OFF after selected cooling delays
Thermostat calls for 2nd stage Cooling
& Dehumidification
Y/Y2 & Y1 & G & (DH)*
ON
Compressor ON, Fan ON after delays at 80% of the selected Cooling
CFM
OFF
Compressor OFF, Fan OFF after selected cooling delays
Thermostat calls for 1st stage Heat
(Heat pump heating mode)
Y1 & G
ON
Compressor ON, Fan ON after delays at 80% of the selected Heat
Pump CFM
OFF
Compressor OFF, Fan OFF after selected Heat Pump delays
Thermostat calls for 2nd stage Heat
(Heat pump heating mode)
Y1 & Y/Y2 & G
ON
Compressor ON, Fan ON after delays at selected Heat Pump CFM
OFF
Compressor OFF, Fan OFF after selected Heat Pump delays
Thermostat calls for 3rd stage Heat
(Electric Heat)
△
W1 & W2
ON
Fan ON at selected Heat CFM, 1st stage & 2nd stage of Heat ON**
OFF
1st stage & 2nd stage of Heat OFF, Fan OFF
*The 24 VAC is removed is remove from DH when there is a call for dehumidification
**Electric heat elements are controlled by relays with a delay sequence from Rectifier timer board on the relays
△
The thermostat must provide Dual Fuel option or a Fossil Fuel kit must be used (electric heat elements & Heat pump must not run at the same time)
▼
Jumper J2 on the electronic board provide connection between W1 & W2. Remove it for 2 stage Electric Heat using a 2 stages thermostat.
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