Walking around in your home and noticing something isn’t right with your heating system may prompt you to check the thermostat to see if someone turned it down. Once you check it and see that it’s set properly you realize you may be having some issues with your HVAC unit. Some systems such as heat pumps have an emergency heat setting that you may be able to use to heat your home until a repair technician can come out and fix it. But when should you really use emergency heat and more importantly how long should you leave it on. These questions are addressed in this article.
What Exactly is Emergency Heat?
During normal operation of your heat pump it will have two separate heating methods. The first is to use a reversal of freon to heat up the interior of your home. But while this is happening the exterior part of the heat pump is getting cold. Coupled with the fact that it’s outside it could appear to completely freeze over.
When this happens a secondary heating process starts to continue to send warm air into the home and the changeover valve on the heat pump reverses the freon flow causing the exterior coil to heat up and melt any ice or frost that has accumulated on it. During this ‘defrost cycle’ the secondary system is heating the home.
This secondary system is considered the emergency heat. It can be powered by electric, natural gas, propane (LPG), or heating oil. The secondary system still uses some of the components of the main heat pump. Once the heat pump completes the defrost cycle then the emergency heat is turned off and the heat pump warms the home using heat produced by the freon coils in the system.
This process happens over and over again in a system. And it’s normal for the emergency heat to come on many times during the day or night if it’s cold outside. Typically, the colder it is outside the more the heat pump will need to defrost, meaning the more times emergency heat will be used.
The Problems with Emergency Heat
Many times the emergency heat isn’t as energy efficient as the heat pump. In fact, when the it’s on the unit may be using double or even triple the normal energy use. Although when the emergency heat is used during normal cycles they don’t stay on long.
When Your Heat Pump Stops Working and you start to get cold in your home you can use the emergency heat sometimes to stay warm. But only if the components that have failed are not part of the secondary heating system. Components such as a blower motor are used by the initial heat pump and the secondary system. If this fails you won’t be able to use the emergency heat at all.
How Long Should You Use Emergency Heat?
The emergency heat setting on your thermostat is only in case of, well, emergencies. If your unit stops and it will take a day to get a repair technician out to look at it then running the emergency may be okay to use. However, it’s not designed to continually heat a home for days. Plus, with the energy consumption of the emergency heat, if you were to let it go for days on end your energy bill would be through the roof. Only use the it when you really need it.