Hi,
Last night at 5am my new HP ran its circulation pump for 4 hours but didn’t do any heating.
I haven’t put anything in the schedule of the user app for the HP to do anything at this time. Not DHW, not Central Heating.
Is this normal behaviour? Perhaps frost protection for the outdoor unit?
Mine did the same last night, I’m fairly sure it’s frost protection. You can adjust the speed of the pump in the MMI settings if you don’t want it going mad.
I think it is probably water pipe freeze prevention (for the outdoor pipes) rather than frost protection (which is to protect the house/indoors from freezing up). However, they both can cause sampling by pumping water around. I disabled frost protection on mine because I have an external thermostat and it caused compressor to come on when I was setting the heating back overnight.
There is a pump limitation setting which you can set to 50% during sampling to reduce overnight pump noise/excessive power wastage (I found that the settings on mine didn’t match the displayed values so I had to use a different value to reduce the speed but seems to be mostly only my model that has this issue)
