We find that when SunPump runs a long time in sub-zero weather, a layer of frost or ice can build up. While some frost is normal, too much will reduce the performance of the panels. If there is no black visible on the panels, let's consider activating the built in Defrost Program. It involves the 4-way reversing valve. and It needs two things to function here are the steps.
- Attach the Coil Temperature copper-colored NTC 5K sensor bulb to a panel, (no to the suction copper line), to measure the combination of ambient air temp and panel temperature as effected by the refrigerant flow.
NTC 5K Thermister bulb sensor
2. Access the Parameters.
ON button held for 4 seconds reveals Lock Icon goes off and back-light comes on. CLOCK+ARROW UP held together for 4 seconds reveals P1.
Set the defrost on temperature in parameters, from default of -15 C to -5 to -2 C. as the set point, and the duration of 3 minutes, with a timer frequency of every two hours as a starting point. Your climate and home heating load will vary, so adjustments are expected.
Below is a reference of button and functions, your model may be a little different in style. Manual is attached below for reference.
