Understanding Auxiliary Heat: Staging, Lockout Settings, and How to Save on Energy Costs

If you have a heat pump, you’ve probably seen the term “Aux Heat” pop up on your thermostat—sometimes followed by a noticeable jump in your power bill. At Eco Heating & Cooling, we get a lot of questions from homeowners across Dothan, Enterprise, Ozark, Headland, and the surrounding Wiregrass area about auxiliary heat staging and lockout settings. Understanding how these features work can make a big difference in comfort, efficiency, and long-term system performance.

This guide breaks it all down in simple terms so you can make informed decisions about your heat pump.

What Is Auxiliary Heat (Aux Heat)?

Auxiliary heat, often called Aux Heat, is a secondary heat source built into most electric heat pump systems. In our area, this is usually electric heat strips installed in the air handler.

A heat pump works by moving heat from the outdoor air into your home. Even in cold weather, there is still heat available outside—but as temperatures drop, it becomes harder for the heat pump to extract enough heat on its own. That’s when auxiliary heat steps in to help.

Aux heat is designed to:

• Support the heat pump during very cold outdoor temperatures

• Help the system recover faster when indoor temperature drops significantly

• Maintain comfort during defrost cycles

The key thing to remember: auxiliary heat uses much more electricity than the heat pump itself.

What Does “Heat Staging” Mean?

Heat staging refers to how and when different levels of heating are activated. Modern heat pump systems can have multiple stages, such as:

• Stage 1: Heat pump only (most efficient)

• Stage 2: Heat pump + partial auxiliary heat

• Stage 3: Full auxiliary heat (least efficient, highest energy use)

A properly staged system allows your heat pump to do most of the work while only bringing on auxiliary heat when absolutely necessary.

Why Proper Staging Matters

If aux heat comes on too quickly or too often, you may experience:

• Higher electric bills

• Short cycling

• Uneven indoor temperatures

• Excessive wear on heat strips

Correct staging helps balance comfort and efficiency, especially during Wiregrass winter weather where temperatures fluctuate.

What Is an Aux Heat Lockout Setting?

An aux heat lockout prevents the auxiliary heat from turning on above a certain outdoor temperature. This setting is controlled either by the thermostat, the system controls, or an outdoor temperature sensor.

For example:

• Aux heat locked out above 35°F

• Aux heat allowed below 35°F

This means your heat pump will handle heating duties alone until the outdoor temperature drops below the lockout point.

Why Lockout Settings Are Important

In our climate, temperatures often hover in the 40s and 50s during winter. Without a proper lockout:

• Aux heat may run unnecessarily

• Energy costs can increase significantly

• The system may rely on heat strips when they aren’t needed

A properly set lockout ensures your heat pump operates efficiently while still protecting comfort during colder nights.

Common Signs Your Aux Heat Settings Need Adjustment

If you notice any of the following, it may be time to have your system checked by a professional:

• “Aux Heat” frequently displayed on your thermostat

• Higher-than-normal winter power bills

• Warm air that feels excessively hot or dry

• The system switching to aux heat during mild outdoor temperatures

• Difficulty maintaining consistent indoor temperatures

These issues don’t always mean something is “broken”—often, it’s a matter of settings, staging, or thermostat configuration.

Thermostat Settings Play a Big Role

Your thermostat is the brain of your heat pump system. Incorrect settings can cause aux heat to activate more often than necessary.

Key thermostat factors include:

• Temperature setback size (large changes trigger aux heat)

• Recovery settings

• Outdoor temperature lockout configuration

• Heat pump balance point

• System staging delays

For example, setting your thermostat back 6–8 degrees overnight may cause the system to engage auxiliary heat in the morning to recover quickly. Smaller setbacks (2–3 degrees) are often more efficient for heat pumps.

How Eco Heating & Cooling Optimizes Aux Heat Performance

At Eco Heating & Cooling, we don’t take a one-size-fits-all approach. Every home and system is different. During a professional maintenance or service visit, we evaluate:

• Heat pump capacity and efficiency

• Condition and sizing of auxiliary heat strips

• Thermostat programming and compatibility

• Outdoor temperature sensor operation

• Proper staging and lockout temperatures

• Home insulation and airflow factors

Our goal is to maximize heat pump runtime while minimizing unnecessary auxiliary heat use—keeping you comfortable without wasting energy.

Energy Savings and Long-Term Benefits

Optimizing aux heat staging and lockout settings can lead to:

• Lower monthly electric bills

• Improved indoor comfort

• Reduced strain on heat strips

• Longer system lifespan

• Fewer winter breakdowns

Many homeowners are surprised to learn that a simple settings adjustment can make a noticeable difference in performance and cost.

When to Schedule a Professional Check

You should consider scheduling service if:

• You’ve recently replaced your thermostat

• Your system was installed by a previous homeowner

• You notice frequent aux heat activation

• Your power bills spike during mild winter weather

• Your system hasn’t had a recent maintenance visit

A trained HVAC professional can verify that your system is operating as efficiently as possible for our local climate.

Trust Eco Heating & Cooling for Heat Pump Expertise

Serving the Wiregrass area since 2015, Eco Heating & Cooling specializes in heat pump diagnostics, maintenance, and optimization. Whether you’re in Dothan, Enterprise, Ozark, Headland, or nearby communities, our team understands how Alabama winters affect heat pump performance.

If you’re unsure whether your auxiliary heat settings are working for—or against—you, we’re here to help.

📞 Call Eco Heating & Cooling today to schedule a professional heat pump evaluation and make sure your system is keeping you warm efficiently all winter long.