Check Emergency Heat Operation (Heat Pumps Only) - Aprilaire 8570 Safety And Installation Instructions Manual

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.
TROUBLESHOOTING – EMERGENCY HEAT OPERATION
Symptom
Thermostat does not call for heat
Emergency Heat does not come on at all
Fan comes on before heat starts, or
Fan does not come on with heat
• 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.
Cause
Minimum-off times. Change the mode to OFF first, then change the mode
to EMERGENCY HEAT and make a call for heat.
RH terminal not connected – see wiring diagrams.
Heating equipment power not on.
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
controlled internally by the heating equipment.
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