Introduction
Quick show of hands, how many of you like being in a constant state of confusion? If we could see you through your screen, I doubt we’d see any hands raised. Being confused or unsure of what to do is one of the most frustrating feelings there is. And it’s the last thing we want to be feeling as we icily stare at our thermostat in our chilly house in the middle of winter. A study found that about 40% of programmable thermostat owners did not use programming features and 33% had programming features overridden. That’s a lot of people who feel like staring at the dial is most similar to staring at the sun. That’s why we decided to start the Understanding Your Thermostat series, to be a resource for anyone looking to get out of this state of confusion. In this article we’ll dive into EM heat, and we’ll tell you what it is, why it exists, and when to use it. We’ll also address common misconceptions or myths about EM heat while dropping some facts that you can take all the way to the bank. EM Heat 101, let’s begin!
What Is EM Heat?
Electromagnetic heat. Just kidding. EM heat simply stands for emergency heat. And if you guessed that emergency heat was meant to be used in case of a heating emergency, you get a golden thermostat sticker (it’s in the mail). But what is actually happening when EM heat is turned on? EM heat is essentially a backup heating system that can be set to automatically trigger or can be manually triggered when the primary system isn’t heating your home as needed. EM heat can be provided through a variety of heating systems, gas, oil, electric, and others, but the most common primary heating system that utilizes EM heat backup is a heat pump. And to fully understand EM heat, you need to know a thing or two about how a heat pump works.
Heat Pumps
Heat pumps are a method of heating that is increasing in popularity. For two years running (2022, 2023) heat pumps outsold gas furnaces and with many leaders at the state level committed to increasing heat pump installations, it’s safe to say it’s a heating option that’s here to stay. That’s because heat pumps are highly energy efficient and environmentally sustainable. Heat pumps provide both heating and cooling functionality, but for our heating conversation, they work by taking heat from the outside air and distributing it into your home. And while this incredibly energy efficient process provides the primary benefit of the heat pump system, it also creates the need for the EM heat setting. As temperatures approach and drop below freezing heat pumps work less efficiently, that’s where the backup system comes in. In these scenarios the heat pump will work in tandem with the backup system to continue to maintain your heating level. What EM heat setting does specifically is bypass the primary heat pump altogether and heats your home entirely off the backup system.
Why is EM Heat Important?
EM heat is a safety blanket meant to keep you warm if your heat pump stops working. Heat pumps can ice over or break down mechanically and if they do the needed repairs will need to be done by HVAC professionals. The EM heat functions to shut the primary system down, preventing further damage if there is a mechanical issue or allowing time for deicing if the heat pump has frozen. Most homes will maintain their current heat level for about eight hours but after that the temperature will begin to drop. The process typically happens even faster in older homes which tend to be less insulated than their newer counterparts. All this means that without a functioning EM heat system, you could be putting your safety at risk.
When Should I Use EM Heat?
HVAC experts are aligned in saying that EM heat should be used when primary heating systems are not functioning. It is important to remember that EM heat does mean extra heat. It’s a different method of heating, and typically a less efficient one than the heating system it’s backing up. EM heat can be provided from numerous sources, gas, oil, electric heating strips, but in standard operating conditions a heat pump is more efficient than any of those other sources. Another important note is that EM heat does not defrost a heat pump. Giving the heat pump time may allow it to defrost, but the EM heat system doesn’t directly help your heat pump thaw out. Heat pumps typically have a separate defrosting system that is set to automatically activate. If the defrost cycle for your heat pump doesn’t seem to be turning on or working correctly it is important to contact an HVAC professional.
EM Heat: True and False
Now that we’ve learned a little bit about EM heat, it’s time for a quiz. Not really, didn’t mean to scare you. No, now it’s time to address some common statements people make about EM heat and let you know whether these statements are true or false. Much better.
1. Using EM heat raises heating costs.
The answer is true, or at least most likely true. Remember EM heat is a backup system that can be provided from various heating sources, but pretty much all of them are less efficient than a properly working heat pump system. This is especially true for a common source of EM heat, the electric heat strip. Electric heat strips use significantly more energy to run and can make your heating costs skyrocket if you have to use it for an extended period. One important thing to note however, is that if the backup system switches on as a result of the heat pump not being able to provide the necessary heat, even if it is less efficient, it is still providing the critical service of keeping your home at the desired or at minimum, a safe temperature. That is to say, if you need it, don’t fret over the extra cost, it’s better to be warm and cozy and a few dollars poorer than to be a penny-pinching popsicle (no offense intended).
2. EM heat will heat your house faster.
The answer is false. Once again the scenario does matter because if the primary system is incapable of providing the necessary heat then EM heat will be faster (any time is sooner than never). However, comparing the primary heating system to EM heat when the primary heat is functioning correctly does not provide a discernible advantage to how quickly your home will heat up. Coupled with the previous fact that EM heat is almost always more expensive to run, we would not recommend switching on the EM heat to get warm quicker. And again, EM heat is not extra heat. When you turn on EM heat both systems are not running. The secondary heating system is running instead of the primary system. And if it makes it easier to remember, think of the primary system as the starting players and the EM heat as the second string and then remember the starters are the starters for a reason.
3. Aux heat and EM heat are the same thing.
This is false. While similar in that they are both referring to the same backup heating system, they aren’t doing the exact same thing. Aux, or auxiliary heat, is an automatic activation of the backup heating system to help provide additional heat when the primary heat pump is falling short. Typically that means when there is a disparity between the set temperature on the thermostat and the actual temperature. The difference between auxiliary heat and emergency heat is that auxiliary heat typically is an automatic setting where EM heat is manually activated. Critically, auxiliary heat will often work with your heat pump as opposed to being on instead of it, as in the case for emergency heat. That makes auxiliary heat a part of the regular functioning of your heating system whereas EM heat is used as a response to an emergency and most likely improper functioning of your system.
4. EM heat can be an early warning sign for needed maintenance.
This is true. Some users have reported intermittent involuntary activation of their EM heat system. For many this has signaled a malfunction in the heat pump compressor. This is another reason why it’s critical to know the difference between different settings in your heating system. Auxiliary heat is meant to turn on automatically and intermittently to help the primary heating system, but if the EM heat is meant for manual activation and signals that the primary system is having a problem. If your heating system is behaving unexpectedly, don’t wait for extreme weather conditions to find out if your system needs repairs. Contact an HVAC professional if you suspect your heating isn’t operating to full capacity or better yet schedule routine maintenance to help avoid costly and untimely repairs.
Conclusion
Now you are all experts on EM heat and are one step closer to understanding your thermostat. Your heating and cooling systems are complex systems but HVAC experts like our technicians here at Burkee are there to be your guides. Burkee’s HVAC technicians go through tech school, get their EPA certification, and complete a minimum 600 hours onsite training with Burkee’s field supervisor, as well as participating in continuing education as technologies change. With this expertise, HVAC technicians know what it takes to efficiently heat and cool the different spaces in your home, so you’ll have the right systems for your home, running at maximum efficiency. HVAC technicians also perform critical preventative maintenance. At Burkee we offer our Comfort Club Maintenance Plans to make sure routine maintenance stays routine. At the end of day heating and cooling systems help us live in comfort, and comfort is what makes you feel at home. So when you have an HVAC emergency—or want to help prevent one—call your Comfort Professionals at Burkee.