10
Emergency Heating System
EMER by passes the HEAT PUMP to use the heat source connected to terminal E on the thermostat. EMER is
typically used when compressor operation is not desired, or you prefer to use the back-up heating system only.
1. Move the SYSTEM switch to the EMER position. EMER will blink on the display.
2. When the (FA)st heating cycle is selected in the configuration menu, (See configuration menu item 2), the
thermostat will call for Emergency heat at 0.5°F below the set-point, and turn off at set-point. When the (SL)ow heating
cycle is selected, the thermostat will call for Emergency heat at 1.5°F below the set-point, and turn off at set-point.
As the thermostat calls for Emergency heat, the display will show Heat On AND +2, EMER will display flashing, and
HEAT PUMP will be blank. All these indicate Emergency heating is operating. If all functions operate properly, the
thermostat is properly installed.
Summary of Contents for T21HTW-0
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