Should auxiliary heat activate when the heat pump enters defrost mode?

When a heat pump enters defrost mode, the primary function is to melt any ice that has accumulated on the outdoor coil. This process is essential for maintaining the efficiency and functionality of the heat pump in cold weather. During defrost mode, the heat pump temporarily reverses its operation, causing the indoor coil to become colder and potentially lead to cold air being circulated indoors.

Activating auxiliary heat during this phase serves an important purpose. It provides supplemental heating to counteract this drop in indoor temperature and ensures that the occupants remain comfortable even as the heat pump is momentarily less effective at heating the space. The auxiliary heat helps to offset the cold air that circulates through the indoor environment as a result of the defrost process.

Thus, turning on auxiliary heat when the heat pump is in defrost mode helps to maintain comfort and responds to the cold air effects caused by the operation of the heat pump in this specific situation. This approach is particularly important in climates where the temperature can drop significantly, and maintaining indoor comfort is essential.