What Is EM Heat On A Thermostat And When Should You Use It?

The EM heat setting, short for emergency heat, can be a bit confusing for homeowners, but understanding its purpose and how it functions is important for making the most out of your heating system. EM heat is a secondary heating mode found on some (but not all) thermostats, particularly those used in heat pump systems. Heat pumps are energy-efficient devices that cool and heat your home by transferring heat between outdoor and indoor environments. In below-freezing temperatures or when the heat pump encounters issues, it can begin to malfunction. This is where the EM heat setting comes into play.

If your heat pump is having issues and the emergency heat doesn't automatically spring to life, you can manually turn on the EM heat function. When you switch your thermostat to the EM heat setting, you are manually activating the auxiliary heating system. This bypasses the heat pump and directs power exclusively to a backup heat source. Continuously using this setting isn't advised due to higher energy consumption, which means less money in your bank account.

When you should use EM heat

While EM heat is a valuable backup option, it's important to revert to the regular heating mode as soon as the issues requiring its activation have been remedied. The heat pump is designed for efficiency, and relying solely on the emergency heating system isn't an economically smart idea. That's because the emergency heat setting, especially if powered by electricity, uses much more energy – in some areas, the cost of using it consistently can increase your utility bill by over 500%.

In addition to increasing your monthly bills, using your emergency heating system as your primary source of warmth can also put considerable strain on the backup system. That means more unnecessary wear and tear, which can ultimately lead to more money being spent on repairs that could have otherwise been avoided. Don't forget to have HVAC professionals come and inspect your system on an annual basis to prevent any unexpected winter surprises.

Don't rely on it for routine use

There are two primary scenarios in which you should consider using the emergency heat setting on your thermostat. The first situation is when outdoor temperatures plummet to freezing levels. During these frigid cold snaps, the EM heat setting automatically kicks on and activates the auxiliary heating system, providing supplementary warmth. This backup heat source ensures that your home remains comfortably cozy even in the harshest winter conditions.

The second circumstance where the emergency heat setting can be used is if your heat pump experiences a malfunction. In situations like this, manually switching your thermostat to the EM heat setting is a valuable, albeit temporary, heating solution. By going this route, you can ensure that you and your home stay nice and warm, however, you should contact an emergency HVAC repair specialist as soon as possible to address the issue and prevent overworking your auxiliary heating system.