10.CHECK EMERGENCY HEAT OPERATION (Heat Pumps Only)

Notes:

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

1. Set the thermostat to the OFF mode.

2.Set the thermostat to the EMERGENCY HEAT mode.

With the O/B configuration setting in the B position (ON), the O/B terminal will be on in the Emergency Heat mode. In the O position (OFF), the O/B terminal will not be on in the Emergency Heat mode.

3.Raise the temperature setting above the room temperature to activate Emergency Heat. The mode display will change from “EHEAT MODE” to “HEATING”, which will flash, when the thermostat is calling for heat. Fifteen (15) seconds must elapse between each stage. Verify the correct outputs are on according to the configuration settings shown below:

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 ELECT/GAS dip switch – ELECT 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.

 

 

 

 

Single/Multi

The same outputs come on

 

 

Configuration Settings

HP/HC

regardless of how these are set.

 

 

 

 

 

Elect/Gas

Elect

Gas

 

 

 

 

 

 

Aux. Ht. Stages

The same outputs come on regardless of how these are set.

 

 

 

 

Outputs Energized

1st Stage Emer. Heat

W1, G

W1

 

 

 

2nd Stage Emer. Heat

W1, W2, G

W1, W2

 

 

 

 

 

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Aprilaire 8570 installation instructions To Emergency Heat and make a call for heat, Single/Multi Same outputs come on, Gas