The P02 error occurs when the R410 Refrigerant Pressure is too high. When the error occurs the pressure gauge on the side of the unit will exceed 600PSI. 

Fan Blade(s): Check to see that the fan blades on the unit are clean and free of debris and clean has necessary. The fan must be able to turn freely, and uniformly. If you see any fan blade damage, or if the fan is shaking erratically you may need to replace the fan blade. 

Air Lock: A very common cause of the P02 error is air in the hydronic system. Make sure you bleed the lines appropriately  to assure their aren't any air locks. 

Faulty Readings Check for continuity across corresponding pressure switch.


Disconnect Cn32 from the control board, and check for continuity on the sensor line.  

If you do not have any continuity on that sensor, the sensor may need to be replaced. Please contact "Arctic Heat Pumps".