The Emergency Heat Switch on a Heat Pump confuses a lot of people. What is it? When do I use it? Do I turn it on when it’s really cold? All these are great questions! Heat pumps need a supplemental heating source. Especially when the weather is below 40 degrees. These supplemental heating sources are things such as the electric resistance heating at the indoor unit, gas, oil or even hot-water back-up systems. Supplemental heating sources are known as “second-stage” or “back-up” heating. Your heat pump only is the “first stage” heating. Emergency Heat is when you use your “second-stage” (supplemental heat) by itself without using your “first stage” (heat pump)
So when should you use your Emergency Heat? Exactly as the name implies, in emergency situations only. It’s used when there’s something wrong with your “first stage” heat. For example, if your house is not warm and it’s because something has happened to your outdoor unit, then it’s time to turn Emergency Heat on and call for service. When you turn on Emergency heat, this will only turn on the indoor unit and back-up heat. Please call to get service when this happens. Having Emergency Heat on can and will be more expensive to run. This is why it is only used in an emergency situation.
**Note that if your Emergency Heat light is on but your thermostat is NOT set to Emergency Heat, this is an indicator there’s a problem with your heat pump and you should call for advice and service.**
Auixiliary Heat will turn on automatically when heat can no longer efficiently transfer heat from the outside air to heat pump. This is when the outside is around 35-40 degrees and the indoor temperature is around three degrees cooler than the thermostat setting. The thermostat will sense this and turn on electric heat strips automatically turning on the “AUX” heat light. This will provide additional heat as needed.
It does need to be noted, if your thermostat stays in “Aux Heat” even when temperatures outside rises, you should call to have it serviced. Auxiliary heat uses electric resistance heating, which is much less efficient than your heat pump. Therefore, a heating system stuck in AUX heat will run up an energy bill. If you have a heat pump, it is best to increase your heat setting by only two degrees at a time to prevent your auxiliary heat from operating.
If you have any questions, please don’t hesitate to call us! We are always here to help as much as we can!