Friedrich SS08M10 Service & Parts Manual page 26

Heat Pump With Electric Heat Operation
This heating is more complex due to the possibility of two heating methods. If the ambient indoor temperature is be-
low the heat demand threshold (1.5˚F below the heat set point temperature), and the compressor is not locked out,
turn on compressor. If the ambient indoor temperature is 0.25˚F above the heat set point turn off the compressor.
If the compressor is locked out & electric heat is available:
1. Turn on the electric heat until the compressor is not locked out.
2. After lockout, turn off the electric heat, wait 5 seconds, then turn on the compressor.
If Electric Heat is Available
After the Heat button is initially pressed, the unit will run the electric heater first until the initial set point is satisfied (Hot
Start Feature). After the initial start, the unit will switch to Heat Pump heat and decide between Heat Pump heat and
Electric heat based on the following two monitored conditions:
Condition 1
If the outdoor coil temperature sensor drops to 30 ˚F or less for 2 consecutive minutes, the unit will switch to electric heat
if available. Thereafter, the unit will switch back to Heat Pump heat if the outdoor coil temperature sensor rises to 45 ˚F or
greater.
If Electric Heat is not available (out of order) and the outdoor coil temperature sensor drops to 30 ˚F or less for 2
consecutive minutes, then the compressor and fan will turn off. Thereafter, the unit will switch back to Heat Pump heat if
the outdoor coil temperature rises to 45 ˚F or greater.
25