What Is Emergency Heat? Is It A Good Idea To Turn On EM Heat When It’s Freezing Outside?
The Emergency Heat setting on your thermostat can be a lifesaver in frigid climates.
Heat pumps are great at keeping your home warm in the winter and cold in the summer. However, they come with certain limitations, such as an inability to warm when the outdoor unit freezes in icy conditions.
That’s where the Emergency Heat option comes in. But what is this setting, and how should you use it?
This blog will answer all these questions about your heat pump’s emergency heat mode.
What Is Emergency Heat?
The Emergency Heat setting is for precisely as its name implies – emergencies. While heat pumps are without a doubt very energy efficient and reliable, they can only warm your home when outside temperatures are above a specific limit.
To explain that to you, let’s look over how heat pumps work. Heat pumps don’t create hot or cold air. Instead, they work by extracting heat from the outdoor and using it to warm your home. As long as the temperature is above 40F, this process works seamlessly. However, below this temperature, the heat pump can’t find enough heat to transfer and fails to keep your home warm.
In times like these, your HVAC system will use Emergency Heat to help you stay warm. This system is a backup heating source for your heat pumps. Usually, this source comes in electric resistance heating (in the case of all-electric heat pumps). But this backup heating could also be oil, gas, or water systems.
Emergency heating comes on automatically, but you also can turn it on manually using the button for EM heat on your thermostat. But we don’t recommend you turn it on yourself and let your system decide when it needs the backup source.
When Should You Use Emergency Heat?
Like we’ve already said, Emergency Heat is for emergencies. You might be tempted to run this setting on freezing days, but we don’t recommend doing that unless the system turns it on automatically.
So when should you use Emergency Heat? You should only manually turn on the backup heat system if you’re experiencing issues with your heat pump. You can utilize this heat source until your HVAC expert can come and have a look at your system.
How Does Emergency Heat Work?
Most heating systems have more than one heat source installed, one as the primary source and another as a backup or secondary source. When your system switches to Emergency Heat, a red indicator light will come on to let you know that you are using the backup heat source.
In the heat pump’s emergency heat mode, no signal is sent to the outdoor unit when the heat pump goes into warming mode. Instead, only the indoor unit and the backup source, which is also located inside the indoor unit, are turned on. As a result, the system will run more like a traditional heating system than a heat pump (meaning it’ll now start generating heat instead of transferring it).
Heat pumps use lesser energy than furnaces when they work as intended. However, this can change when running in the Emergency Heat setting.
Is EM Heat More Expensive to Run?
The answer to this depends on the type of heat pump you own. All electric heat pumps are indeed very costly to run. But if you have oil or gas heat as your backup system, the answer will depend on the efficiency of your system and the cost of the fuel. The price won’t be as high as running an electric heat pump on Emergency Heat, but it will undoubtedly be higher than the general running cost of your heat pump.
Keeping in mind the steep cost of using Emergency Heat, it is better to use this setting only when there are real emergencies. Be sure to turn the EM heat setting off once your heat pump is functional again because while the system comes on automatically, it won’t turn off until you do it manually. Some advanced models do turn it off when the backup isn’t needed, but it’s always a good idea to check if it’s unnecessarily on.
5 Things You Need to Know About the Emergency Setting on Your HVAC System
Before you click that button for EM heat on your thermostat, you should know a few basics.
1. Emergency Heat is Not a Replacement for Your Primary Heating System
Your primary heating system, the heat pump, should be enough to keep your house warm and cozy in even the coldest weather. It’s only in periods of extreme cold that you might need a backup system to keep up with your heating needs. However, if you find yourself often having to run the EM heat, your HVAC system might not be sufficient for your home, or it might need maintenance. Check-in with an expert to fix the issue.
2. Your HVAC System May Not Have an Emergency Heat Setting
If you live in an area with a warmer climate where the cold is always moderate and temperatures stay above 40 degrees, your HVAC system might not have an Emergency Heat setting at all. However, you don’t need to worry about this since the EM heat option is designed chiefly for temperatures consistently close to or below freezing.
3. Check Your HVAC System for Damage Before Running the Emergency Setting
If your HVAC system is not keeping up, you should check for damaged components before switching the Emergency Heat on. While it is true that this setting is for emergencies, it’s still better to know what sort of damage your system has. Not only will this make your service call easier, but it will also prevent any further damage to your system if you address the issue quickly.
4. Emergency Heat Light Staying on Could Signal a Problem with Your Heat Pump
If your system is running in Emergency Heat, it’s normal for the EM heat indicator light to stay on until you turn it off. However, if you’re not using the Emergency Heat mode and the indicator is still on, there could be a problem with your heat pump.
In this case, you can try and troubleshoot the issue yourself or call an expert for help.
To do the process yourself, you first need to count the number of flashes since certain units flash a code that you can then check in the manual to determine the problem. These flashes can range from two to nine. Next, you should turn your thermostat off and wait 30 seconds before powering it back on to restart your system.
Once you’ve done that, shut down the indoor unit and turn it on after five minutes if the light continues to blink. If your system has shut down during inclement weather, this will fix that. Lastly, wait ten minutes and inspect the outdoor unit to see if it is running. If the light on the thermostat is still on, turn off all the circuit breakers located in an electrical panel next to the outdoor unit. You can also check the user manual to find the circuit breakers. Then, turn the circuit breakers on again after a few minutes.
If the icon for EM heat on the thermostat still doesn’t go away, schedule an appointment with a professional.
5. Emergency Heat Could Be a Lifesaver
Your heat pump’s emergency heat mode can be a lifesaver at times. For example, imagine your primary heating system goes out in the dead of winter. This issue can be potentially life-threatening. In times like these, the Emergency Heat setting can be your only line of defense, so you should make sure that the backup system stays in usable condition.
Emergency Heat is a backup heating source that your heat pump uses when it cannot keep up with your heating needs or breaks down. While many people switch this system on whenever they feel that the temperatures outside are too low, this is not wise since the EM Heat system is more expensive than a traditional heat pump. Therefore, to keep using your system efficiently, only use this system when your primary heat source is non-functional.