HVAC and New Construction, Home Additions and Multi-Family Dwellings

When to Switch to Emergency Heat Mode

The emergency heat button on a heat pump thermostat is a source of confusion for many people. This is because many people hardly understand when to use the emergency heat switch. The assumption by many people is that heat pumps hardly work in cold, chilly climatic conditions and therefore, they opt to use the emergency heat every time it gets extremely cold. However, nothing could be further from the truth. Read on to find out why.

Emergency heat: What is it?

Heat pumps often come with a supplemental source of heating. Normally, it comes in the mode of electric resistance heating at the indoor unit. The supplemental heat may be referred to as back-up or second-stage heating, assuming that the first-stage is the heat pump exclusively. Therefore, when you turn on emergency heat, you are simply using your supplemental heat or second-stage exclusively, without the help of the heat pump or first-stage heat. Heat pumps and thermostats have various ways to determine when the supplemental heat is needed to help out the heat pump, but this is always carried out automatically.

When should you use emergency or supplemental heat?

Just as the name suggests, it's only used in crisis or emergency situations, especially when there's a problem with the heat pump itself or the first-stage heating. Simply put, if you become aware that your home is cold because of the failure of your heat pump to heat properly because a tree crushed it or because of ice build-up, then such scenarios would be ideal to turn on the emergency heat.

What action does emergency heat perform?

Upon switching on emergency heat, a red indicator immediately turns on until you finish using the back-up heat. This simply informs you that you're working in emergency mode. Only the back-up heat will run and not the heat pump.

Is it costly to run the emergency heat?

Part of the reason why it's advisable not to switch to emergency heat without any emergency situation is because it is very expensive to run more so if you rely on electricity for your backup heat mode. However, if your backup system uses oil or gas, then the overall cost will depend on the price and efficiency of your source of fuel. Emergency heat allows you to heat your home in crisis situations until your heat pump is able to be repaired by a HVAC contractor.

Homeowners should avoid switching to emergency heat mode when it's cold. Instead, they should only do so when the heat pump is not working or any other crisis situation.