We have two heat pumps, one for upstairs and one for downstairs.
They are Carriers and are 22 years old (I know we are living on borrowed time).
For each heat pump, there is a 10KW electric heat pack installed in it's air handler.
But I noticed that during the cold spell we are having both heat pumps run for
long periods of time (> hour) when the temp is far below anything they can
extract heat from. I assume all the heat we are getting is from the heat packs
in the air handlers.
Why would the heat pumps be running?
Thanks for any help.