When the temperatures drop in Moncks Corner, SC, many homeowners rely on heat pumps to stay warm. But if you’ve ever looked at your thermostat settings, you may have noticed an option labeled “EM Heat” and wondered what it means. At Pointer Cooling & Heating, we often get calls from customers asking, what is EM heat and when should it actually be used? Understanding this function can help you run your system efficiently and avoid higher-than-necessary energy bills.
What Is EM Heat on a Thermostat?
EM Heat stands for Emergency Heat. It’s a backup heating mode that’s part of a heat pump system. A heat pump usually works by transferring heat from the outside air into your home, even when it’s cold outside. But when temperatures drop very low, or if the outdoor unit fails, the system may not be able to pull in enough heat to keep your home comfortable. That’s where emergency heat comes in.
Emergency Heat uses an alternate heat source, typically electric resistance heating strips or, in some cases, a gas furnace. This backup ensures your home can stay warm when the main heat pump can’t keep up.
How EM Heat Works in Your System
When you switch to EM Heat, your thermostat tells the system to bypass the heat pump and rely only on the secondary heat source. Unlike the normal “auxiliary heat” that automatically kicks on when temperatures dip, Emergency Heat requires you to manually activate it.
In most homes around Moncks Corner, this secondary heat source is electric resistance heating, which works like a giant space heater built into your HVAC system. While it does produce reliable heat quickly, it uses significantly more electricity than your heat pump’s normal operation.
When Should You Use EM Heat?
Knowing what is EM heat is only half the equation — you also need to know when to use it. In general, EM Heat should be used in these situations:
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Heat Pump Failure: If your outdoor unit stops working or is covered in ice, switching to Emergency Heat keeps your home warm until repairs can be made.
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Extremely Cold Weather: In rare cases, if outdoor temperatures are too low for your heat pump to extract enough heat, EM Heat can provide supplemental comfort.
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System Troubleshooting: If you suspect an issue with your heat pump, technicians may ask you to run Emergency Heat to keep the house comfortable while diagnosing the problem.
For everyday cold weather in Moncks Corner, you don’t need to turn on EM Heat yourself. Your system is designed to automatically engage auxiliary heat if needed.
Why You Shouldn’t Rely on EM Heat Too Often
While EM Heat sounds like a reliable option, it comes with a major drawback: high energy costs. Electric resistance heating consumes far more electricity than a heat pump. If left running for days or weeks, your utility bills will climb quickly.
This is why Emergency Heat is designed for short-term or emergency use only. If you find yourself frequently needing Emergency Heat to stay comfortable, it may be a sign that your heat pump is undersized, malfunctioning, or in need of maintenance.
EM Heat vs. Auxiliary Heat: What’s the Difference?
Homeowners often confuse Emergency Heat with auxiliary heat, but they aren’t exactly the same. Auxiliary heat automatically activates when your heat pump alone can’t keep up — for example, when the temperature drops suddenly. In this case, your system uses both the heat pump and the secondary heating strips together.
Emergency Heat, on the other hand, shuts off the heat pump entirely and forces your system to use only the backup heat source. This makes Emergency Heat less efficient and more expensive, but it ensures warmth even if your outdoor unit isn’t functioning.
Signs You May Need EM Heat
Sometimes your thermostat will make it clear when to use EM Heat. But in other cases, you may need to decide on your own. Here are a few signs that Emergency Heat may be necessary:
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The outdoor unit is visibly damaged or iced over
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The heat pump isn’t blowing warm air
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Your system is running constantly without reaching the set temperature
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You hear unusual noises coming from the outdoor unit
If any of these issues arise, switching to EM Heat can keep you comfortable until an HVAC technician from Pointer Cooling & Heating inspects and repairs your system.
Comfort in Moncks Corner
Here in Moncks Corner, winter temperatures can dip into the 30s or even lower, but they don’t usually reach the extreme lows seen in northern states. This means heat pumps work very efficiently for most of the year. Emergency heat may only be needed occasionally, such as during an unexpected cold snap or when a heat pump malfunctions.
Because winters in South Carolina are generally mild, many homeowners may never need to use EM Heat at all. Still, it’s helpful to understand the option and know it’s available in case of an emergency.
Preventing the Need for EM Heat
The best way to avoid overusing EM Heat is to keep your heat pump in good condition. Regular maintenance ensures that your system can perform efficiently even in colder weather. Simple steps include:
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Scheduling professional tune-ups before the winter season
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Changing air filters regularly to maintain airflow
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Keeping the outdoor unit clear of ice, leaves, and debris
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Having your system checked if it struggles to maintain temperature
By staying proactive, you’ll minimize the chance of relying heavily on emergency heat.
Call the Professionals
If you ever have to switch to EM Heat because your system isn’t keeping up, it’s best to call a licensed HVAC technician as soon as possible. Running on emergency heat for too long can send your energy bills skyrocketing and put strain on your system.
At Pointer Cooling & Heating, we specialize in diagnosing and repairing heat pump issues quickly. Whether your outdoor unit is frozen, your thermostat isn’t working properly, or your system needs a tune-up, our team in Moncks Corner is ready to help restore efficient heating.
Final Thoughts
So, what is EM heat? It’s your system’s emergency backup designed to keep your home warm when the heat pump can’t do the job. While it’s an important feature for peace of mind, it’s not meant for everyday use due to the higher energy costs.
If your system frequently requires EM Heat, that’s a signal to call the experts at Pointer Cooling & Heating. We’ll inspect your system, make the necessary repairs, and ensure your home stays comfortable without the extra expense.