I just had a Lennox XP17 heat pump installed. My secondary source of energy is oil hence a dual energy system. As I understand it, if there is a 1 degree difference between the actually temp. in the house vs. the temp set on the thermostat, them the heat pump will kick in and run until the 1 degree temp. differential is overcome. If there is a 2 or more degree difference...(either caused from a sudden blast of cold air or a manual increase of the stat by2 degrees or more) then the oil will kick in until this differential is overcome. This makes sense as a heat pump will take quite a bit longer to get to the temp. as set on the thermostat and you really want it to get there asap.
Now the problem. I have noticed that oil will kick in with only a 1 degree differential but only ocasionally. What would cause this intermitance? The stat is a year old so I am leaning to waive this out as the fault. I am also ruling out the outside temp being below the threshold where the oil is set to kick in. The heat pump could be running 1 minute and the oil minutes later due to just the 1 degree differential.
Any of you HVAC specialists care to share an opinion? Most appreciated.