Aprilaire 8570 installation instructions Check Emergency Heat Operation Heat Pumps Only

8.CHECK EMERGENCY HEAT OPERATION (Heat Pumps Only)

Notes:

1.To avoid the minimum off times during system checkout, always start the check out procedure in the OFF mode.

•Set the thermostat to the OFF mode:

•Set the thermostat to the EMERGENCY HEAT (EMERG) mode:

–The B terminal will energize when in the Emergency Heat mode.

•Raise the heat setting to 5° higher than the room temperature to initiate a heat call. The mode display will change from “E-HEAT MODE” to “HEATING”, which will flash when the thermostat is calling for heat:

–W1 and W2 (and G if GAS/ELEC dip switch is set in the ELEC position) terminals will energize.

•Set the thermostat to the OFF mode.

TROUBLESHOOTING – EMERGENCY HEAT OPERATION

Symptom	Cause
Thermostat does not call for heat	Minimum-off times. Change the mode to OFF first, then change the mode
	to EMERGENCY HEAT and make a call for heat.
Emergency Heat does not come on at all	RH terminal not connected – see wiring diagrams.
	Heating equipment power not on.
Fan comes on before heat starts, or	Change position of ELEC/GAS dip switch – ELEC for electric heat systems
	(fan on with heat call) or to GAS for fossil fuel systems where the fan is
Fan does not come on with heat
	controlled internally by the heating equipment.

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