Why Your Heat Pump Runs Constantly in Cold Weather

White wooden house in winter landscape of Nordic town Tromso, Norway.

When your heat pump runs continuously during the winter, it might seem like something’s wrong—but in reality, it’s often functioning exactly as designed. Heat pumps rely on drawing heat from the outdoor air, and as temperatures drop—especially below 30°F—they need to run longer to keep your home warm. This extended operation is not a malfunction but a key part of how modern heat pumps deliver energy-efficient comfort.

Normal Winter Operation Patterns

It’s completely normal for your heat pump to run non-stop when outdoor temperatures fall below freezing. This is due to your system reaching its “balance point”—the temperature at which it needs to operate constantly to maintain indoor comfort. In colder regions, this balance point may be as high as 30°F. Below that, auxiliary heat may kick in to help your main system.

Advanced systems like variable-speed heat pumps and ground-source models perform more efficiently in extreme cold, but even they require extended run times. You may also notice your unit enter defrost mode briefly to melt any ice buildup on the outdoor coils. This is a normal and essential process for maintaining peak performance.

Why Heat Pumps Run Constantly

Several factors contribute to continuous heat pump operation in winter:

  • Cold Outdoor Temperatures: Efficiency decreases as it gets colder, so longer run times are necessary.
  • System Sizing: An undersized heat pump may struggle to meet your home’s heating demands.
  • Thermostat Settings: Higher settings require more operation to maintain target temperatures.
  • Poor Insulation: Leaky windows, doors, and walls make it harder to retain heat.
  • Maintenance Issues: Dirty filters, low refrigerant, or blocked airflow can cause inefficient operation.

Despite the longer run times, your heat pump can still be up to 300% efficient, transferring more energy than it consumes.

Energy Costs and Extended Runtime

Extended operation doesn’t mean higher costs if your system is working efficiently. In fact, heat pumps are designed to run longer and at lower power compared to traditional furnaces. Because they avoid frequent start-stop cycles, they use energy more evenly and efficiently.

You can expect up to 60% savings on heating costs over older heating systems. Key ways to manage energy use include:

  • Keep your thermostat at a steady 68°F
  • Use the “Heat” setting, not “Auto”
  • Avoid large temperature swings that may activate expensive backup heat

Proper system selection and maintenance will ensure you continue to save—even when your unit runs non-stop.

Cold Weather Performance Factors

Modern heat pumps are built to handle harsh winters. Cold climate models maintain 70% heating capacity even at -15°C (5°F) and some can operate effectively down to -30°C (-22°F). Performance depends on:

  • The system’s HSPF (Heating Seasonal Performance Factor)
  • Your regional climate
  • Whether auxiliary heat is available for sub-freezing temperatures
  • The heat pump’s balance point and design features

If you’re in a colder region, make sure your system is specifically rated for cold weather use.

Signs of Inefficient Operation

If your system runs constantly and you still experience uneven temperatures or high bills, there may be a deeper issue. Watch for these red flags:

  • Frost buildup on the outdoor unit
  • Unusual noises (grinding, squealing, rattling)
  • Short cycling (frequent on/off operation)
  • Cold spots or uneven room temperatures
  • Defrost cycles happening too frequently or for too long

These signs suggest it’s time to schedule a maintenance visit.

How to Maximize Efficiency

Keep your heat pump in peak condition during winter with these simple tips:

  • Replace air filters monthly
  • Clear debris, snow, and ice from the outdoor unit
  • Avoid blocking vents with furniture or curtains
  • Schedule professional maintenance twice a year
  • Use smart thermostats for precise temperature control

Proper maintenance ensures your system can handle the cold and operate efficiently without unnecessary strain.

Contact BPM Heating & Cooling for Heat Pump Service

At BPM Heating & Cooling, we understand the unique challenges your heat pump faces during Frederick winters. Our expert technicians provide professional maintenance, repairs, and new system installations tailored to your home’s needs.

If your heat pump is running non-stop or not performing as it should, give us a call at (240) 200-0887. You can also visit our shop at 300 E 4th St Unit A, Frederick, MD 21701, or schedule service online at bpmhvac.com. We proudly serve residential and commercial customers across Frederick County and surrounding areas.

 

Picture of Bert Miskell

Bert Miskell

HVAC – Master (MD): #75803
Master Plumber/Gas Fitter: #86156

Family is at the heart of everything we do at BPM Heating & Cooling. As a locally owned and operated business, we treat every customer like a member of our own family, delivering personalized service and genuine care.