The PC Error is thrown when the ambient temperature is too high, or too low for the unit to operate. 


Low Ambient Protection (in cooling mode): The low ambient protection for cooling is parameter 40.  The default settings is -1C. This means when the outside temperature drops to -1C or lower, the unit will no longer cool.  This is adequate for most environments, but if you need cooling to work at lower temperatures you can lower this value. 


  1. Unlock the controller (press the power button for 5 minutes)
  2. Press the program button (2nd from left) for 5 seconds... until the unit beeps. 
    • You will now see the #00 at the bottom (this is the parameter)
    • You will also see the VALUE of the parameter in big numbers on the screen
  3. Use the UP/Down arrows to raise the parameter (the small number at the bottom) to 40
  4. Press the program button one time to enter EDIT MODE (the value will begin to blink)
  5. User the UP/Down arrows to set the desired value
  6. Press the program button one time to exit EDIT MODE.
  7. Press the power button one time to exit parameter mode. 


Heating Mode


Low Ambient Temperature Protection: By default, the heat pump will not heat or cool when the ambient temperature is -30C or lower. This parameter setting should not be changed. 


High Ambient Temperature Protection: By default, the heat pump will not heat or cool when the ambient temperature is 57C or higher. This parameter setting cannot be changed.