In my house we only have electric heat available. When it gets too cold, the heat pump no longer keeps up and the resistive heater in the furnace turns on. It i

In my house we only have electric heat available. When it gets too cold, the heat pump no longer keeps up and the resistive heater in the furnace turns on. It is more expensive to use the coils than the heat pump. It is important to understand the environment it is running in to accurately predict your energy costs. The previous owner should have installed one that could run in colder temperatures.