Friedrich KUHL R-410A Service Manual page 25

Heating Mode Control Operation
There are two heating methods: Heat Pump and Electric Resistance Heat.
There are 3 types of units that provide heating: Heat Pump Only (Model YS10M10)
Heat Pump with Electric Heat and Cool with Electric Heat.
Heat Control Operation Heat Pump Only
Once the ambient temperature falls below the Heating Demand Threshold
(1.5 ˚F Below the Heat Set Point Temperature), the heating cycle begins. The fan is turned on 5 seconds later. Once
the ambient temperature has been raised to the Heat Satisfi ed Point (Set point + .25 ˚F), the compressor is turned
off. The fan is turned off 30 seconds later. The fi gure below illustrates the basic heat pump operation.
Heat Control (Heat Pump Only)
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