When Chicago winters hit freezing cold temperatures, sometimes plummeting as low as 5 degrees, many home and business owners may notice their auxiliary heat running for extended periods or frequently turning on and off. This can cause concern, as auxiliary heat typically is not supposed to run all the time. While it’s normal for auxiliary heat to kick in during exceedingly cold temperatures, running it too long may indicate an issue with the heat pump.

If you’ve been noticing the AUX heat icon displayed on your home or business thermostat screen, it’s natural to feel concerned. You might worry about rising energy bills or even fear something is wrong with your heat pump. However, the AUX heat function is designed for specific functions, and it’s not uncommon to see it when the outside temperatures are freezing cold. While it’s normal for the auxiliary heat to turn on under these conditions, if you notice it is not turning off or repeatedly turning on and off, don’t hesitate to reach out to our team at Four Seasons Heating & Cooling so that we can take a look at it and provide you with peace of mind that it is running properly. 

Jump to: What is Auxiliary Heat? | Is It Bad If Auxiliary Heat Comes On? | Common Reasons Your Auxiliary Heat Turns On | How Can I Prevent My Auxiliary Heat from Activating? | Auxiliary Heat Running Too Long? – Contact Us To Have A Look

What is Auxiliary Heat?

The auxiliary heat on a furnace is a secondary heat source, which is usually powered by gas or electric, that activates when the primary heat pump struggles to maintain the temperature inside the home or business. This often occurs during sudden temperature drops or extremely cold conditions, which are not uncommon in the Chicagoland area. Auxiliary heat is particularly useful in colder climates, as it helps the heating system warm your home quickly by providing an extra boost of heat.

Similar to furnaces, when a heat pump alone cannot generate enough warmth, the auxiliary heat will kick in. Typically, the system will energize electric resistance heating strips within the unit to help reach the thermostat’s set temperature. If you notice the AUX heat indicator on your thermostat, this signals that your heat pump’s backup electric resistance heating is in use, working to keep your home comfortable despite the colder outdoor temperatures, which is not something to worry about. However, while it’s having the auxiliary heat turn on is a normal feature, it’s important to ensure your system is functioning efficiently to avoid unnecessary energy use when you notice it is consistently turning on and off. 

Is It Bad If Auxiliary Heat Comes On

It’s not necessarily bad if your auxiliary heat turns on, regardless of if you have a heat pump or a furnace in your home or business. In fact, auxiliary heat is an important part of maintaining your home’s comfort during extremely cold weather when your heat pump needs extra support to warm your home. 

However, auxiliary heat uses a lot of energy, therefore it can lead to higher utility bills if it runs too often or unnecessarily. It’s important to monitor how frequently your auxiliary heat is turning on and ensure your system is operating efficiently to prevent unnecessary energy usage. If you notice it activating too often in milder conditions, or when your thermostat says your home is heated to the desired temperature, it may be a sign your heat pump needs maintenance or adjustments. If you notice this happening, don’t hesitate to reach out to a heat pump technician in Chicago at Four Seasons Heating & Cooling. 

Common Reasons Your Auxiliary Heat Turns On 

There are a few common reasons why your auxiliary heat might turn on, especially during Chicago’s colder weather. While it’s normal for the auxiliary heat to activate in certain situations, understanding why it happens can help ensure your system is functioning properly, and provide you with peace of mind. 

Cold Weather 

One common reason your auxiliary heat may turn on is extremely cold weather, which is not uncommon for the Chicago area. Heat pumps work by extracting heat from the outside air, but as temperatures drop, their efficiency in heating your home or business decreases. When it gets particularly cold, your heat pump might need some extra help to maintain the desired indoor temperature set on your thermostat. In these cases, the auxiliary heat will then kick in to support the heat pump or furnace, making sure your home stays warm even when the outdoor temperatures are especially low. However, if your auxiliary heat is running too long, don’t hesitate to contact our team so we can make sure your heat pump or furnace is running properly. 

Malfunctioning Components

A system malfunction is another common reason why your auxiliary heat may turn on unexpectedly or run for too long. This can happen if there’s a faulty sensor, a miscommunication with the thermostat, or another mechanical issue within the heat pump or furnace. These malfunctions with the heating unit can cause the system to incorrectly activate the auxiliary heat, even when it’s not needed. If you suspect your heating system is malfunctioning, it’s important to consult with an HVAC professional from our team to diagnose and resolve the issue before it causes further damage, ensuring your system runs efficiently and prevents unnecessary energy use. 

Turning Up Your Thermostat

Another common reason your auxiliary heat may turn on is if you drastically increase the temperature on your thermostat within your home or business. When the system detects a significant jump in the desired temperature, it switches to auxiliary heat mode to quickly boost warmth inside. Since the heat pump alone can’t raise the temperature fast enough, the auxiliary heat provides supplemental warmth to heat the house until it reaches the temperature set on the thermostat. This rapid response ensures the inside of your business or home heats up quickly, but can also lead to increased energy use if done frequently.

How Can I Prevent My Auxiliary Heat from Activating?

To keep your auxiliary heat from running too long and help manage energy costs, it’s important to take a few proactive steps. One of the most effective ways to prevent your auxiliary heat from activating is to adjust your thermostat gradually instead of in big increments. Increasing the set temperature by just a degree or two at a time is recommended to keep the auxiliary heat from kicking on. This avoids triggering the need for rapid heating, which would cause an increased need for energy, reducing the cost of your utilities.

Regular heat pump and furnace maintenance is also key to ensuring your auxiliary heat operates efficiently. Scheduling periodic maintenance and tune-ups can help identify any potential issues with your auxiliary heat before they lead to unnecessary energy use, helping your system run smoothly and reducing the likelihood of auxiliary heat staying on for extended periods.

Auxiliary Heat Running Too Long? – Contact Us To Have A Look 

If you’re in the Chicagoland area and suspect that your auxiliary heat isn’t functioning properly for your heat pump or furnace, don’t hesitate to reach out to our team at Four Seasons Heating & Cooling. Our experienced HVAC professionals near you are here to assess your heating system and ensure it’s operating efficiently, especially during Chicago’s harsh winter months. We understand how important it is to maintain a comfortable indoor environment while managing energy costs, and we’re dedicated to providing you with the expert heating service you need. Contact our team today to schedule an appointment and keep your home warm and cozy all winter long!