What Is Auxiliary Heat?

You may think your heater does all the work of keeping your home at the temperature you want it on its own, but it frequently gets extra help from auxiliary heat. This extra help gives your heater an extra boost when outside circumstances prevent its power from being enough to heat your home efficiently. 

What Is Auxiliary Heat and What Does It Mean for Your Heater? 

Most heaters typically work by pulling heat that already exists out of the air to repurpose, but this process is not always possible. If the air is too cold for your heater to heat your home effectively, or if there is ice on your heater, your auxiliary heat may turn on to produce enough extra heat to reasonably fill your home. This “emergency” heating system should only be active when absolutely necessary because overuse is inefficient and can cause excessive wear on your heating system. 

Heat Pump Cannot Produce Enough Heat 

Outdoor temperatures that fall below freezing frequently make it too difficult for your heat pump to produce the amount of heat it needs to bring your home to the temperature you want. When this occurs, your auxiliary heat provides the extra help your heat pump needs to raise your room temperature to your specification. 

Your System Is in “Defrost Mode” 

Your system’s defrost mode is used to melt away ice that has formed on the outside of your heater, restricting it from getting enough heat even if the outside air might otherwise be warm enough. Your heater can typically sense when defrost mode needs to kick in to get rid of ice or frost, automatically turning on your auxiliary heat. Although defrost mode, and your auxiliary heat should automatically turn off once it is not needed, it can also get stuck on this setting and need to be manually adjusted. 

When is it Normal for the AUX Heat to Turn On? 

Your AUX heat may require your attention if it cannot turn itself off when it should, resulting in getting stuck, but several circumstances exist when using it is normal. 

Quickly Increasing the Thermostat

Increasing your thermostat by three or more degrees will frequently turn your AUX heat on because it cannot heat itself that much that quickly. Once the room temperature reaches what you set it at, the AUX heat should turn off and allow the heater to work normally. 

Very Cold Temperatures

Temperatures below approximately 35 degrees Fahrenheit and especially below freezing make it normal for your AUX heat to turn on because your heater cannot make a drastic change on its own. Your AUX heat may cycle on and off or simply stay on if temperatures are below freezing for a prolonged period, but it should turn itself off once they rise to temperatures it can work with more easily. 

Heat Pump Is Defrosting

It is normal for your AUX heat to turn on when your heat pump is in defrost mode. Again, it should turn off on its own once this setting is no longer needed. 

Emergency Heat Setting Is Engaged

Any unusual circumstances that turn on your heater’s emergency heat setting are also normal and acceptable reasons for your AUX heat to turn on temporarily. 

Tips for Avoiding AUX Heat Issues 

Although your AUX heat can be helpful when needed, it can cause your heater to wear out faster than it should if it stays on when it is not needed. Keeping your ducts, heat vents, and the area around your heater clean, replacing the heat pump filter at least every two months, and keeping the rest of your heater well maintained can go a long way toward keeping your AUX heat working properly and avoiding issues. It is also essential to ensure that your emergency heat setting is only used during actual emergencies rather than as a normal heat setting. Its design is not to run consistently or frequently.  

Prepare Your Arizona Home’s AC for Summer 

At Howard Air & Plumbing, we prioritize helping our customers heat and cool their homes as efficiently as possible, which means understanding what might cause your heater to utilize too much auxiliary heat and what you can do to fix it. Contact us today to learn more about getting the most out of your heating and cooling solutions at any time of year!

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