Digital Control Operation
Temperature Display
The Friedrich digital PTAC is shipped from the factory to display the desired room temperature on the LED readout.
The unit can be configured to display the room temperature by simultaneously pressing the ‘Cool’ and ‘High Fan’ buttons for three seconds the display will show an ‘R’ for one seconds to acknowledge the change. The unit will display the setpoint
whenever the ‘Temp’ 
or 
buttons are pressed and then switch back to room temperature.
To revert back to displaying the setpoint only press the ‘Cool’ and ‘Low Fan’ buttons for three seconds simultaneously, the unit will display an ‘S’ for one seconds to acknowledge the change.
ºF vs. ºC Display
The unit is factory configured to display all temperatures in degrees Fahrenheit (ºF). To switch to degrees Celsius press the ‘Fan Only’ and ‘Low Fan’ buttons simultaneously for three seconds. The display will show a ‘C’ as acknowledgement of the change.
To revert back to ºF press the ‘Fan Only’ and ‘Low Fan’ buttons simultaneously for three seconds. The display will show an ‘F’ as acknowledgement of the change.
Cooling Mode
Pressing the ‘Cool’ button while the unit is in any mode, including off, will put the unit into cooling mode. Adjust the temperature readout to the desired room temperature and the unit will cycle the compressor on and off to maintain a comfortable room. The compressor will come on anytime that the room temperature is 1.8°F above the desired temperature. The fan operation is dependent on the fan mode selected, either continuous or cycling. See page 16 for fan cycle control.
Heating Mode
Pressing the ‘Heat’ button while the unit is in any mode, including off, will put the unit into heating mode.
Heat Pump Models (PDH)
When the ‘Heat’ button is pressed initially the unit will energize the electric resistance heat to quickly bring the room to the set temperature. When the desired room temperature falls 1.8°F below the desired set temperature the unit will cycle the compressor on and operate as a heat pump to maintain the room temperature while running more efficiently than resistance heat only models. If the room temperature should fall more than 5°F from the set temperature the unit will run the resistance heater. The fan operation is dependent on the fan mode selected, either continuous or cycling. Dip switch 5 controls the fan mode, see page 16 for setting.
When the outdoor coil temperature falls below 30°F for more than 2 minutes the unit will operate the resistance heaters and not the compressor. When the outdoor coil temperature reaches 45°F the compressor will be allowed to operate again.
Figure 12
Digital Control Panel
Heat/Cool Models (PDE)
After pressing the ‘Heat’ button, adjust the temperature readout to the desired room temperature and the unit will cycle the resistance heat on and off to maintain a comfortable room. The heater will come on anytime that the room temperature is 1.8°F below the desired temperature. The fan operation is dependent on the fan mode selected, either continuous or cycling. Dip switch 5 controls the fan mode, see page 16 for setting.
Emergency Heat Operation
In the event of a compressor failure in heat pump mode the compressor may be locked out to provide heat through the resistance heater. This feature ensures that even in the unlikely event of a compressor failure the room temperature can be maintained until the compressor can be serviced. Dip switch 7 controls the emergency heat setting, see page 16.
Fan Mode
Fan Only
Pressing the ‘Fan Only’ button will run the fan to allow for air circulation in the room without operating the compressor or heater regardless of the room or set temperature. The fan speed selection is made by pressing either the ‘High Fan’ or ‘Low Fan’ button.
Cycle/Continuous
The owner may choose between fan cycling or fan continuous mode based on property preference. (Note: Even heat monitoring and quiet start/stop fan delay only operate in fan cycle mode) Fan continuous mode is used to keep constant airflow circulation in the room during all times the unit is ‘ON’. Fan cycle will conserve energy by only operating the fan while the compressor or electric heater is operating. Dip switch 5 controls the fan mode, see page 16 for setting.
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