I ran water through the pipes as described in the manual to clean them of any debris and dirt then I filled the system with water by closing the drain valve and opening the vent valve at the highest point to allow air to escape. With the circulator pump on I monitored the clear plastic piping to see if air pockets were disappearing. At various times I would open the vent valve to vent any air that was trapped there. I could still see trapped air pockets in the clear plastic pipe a few weeks after I began using the heat pump. Eventually they just completely disappeared as I vented them out.

The manual indicated that the main power to the heat pump should be on at least 12 hours before the heat pump is actually turned on. There is a small electrical resistance heater in the unit to bring it up to temperature. The heater is so small that the power should be on at least 12 hours before heat pump is turned on.