If your heat pump runs constantly in cold weather, it’s easy to assume something might be wrong with your system. However, here’s some good news: That constant operation is not a sign of failure; it’s a sign your heat pump is working precisely as designed by the manufacturer. Modern heat pumps are incredibly efficient heating systems, even in frigid conditions. Understanding how your heat pump operates can help you stay warm without worrying about your equipment or paying for an unnecessary service call or heat pump repairs.
Are Heat Pumps Inefficient in Winter, and Should I Use the Emergency Heat Setting?
A common misconception about heat pumps is that they don’t perform well in winter. While it’s true that heat pump efficiency decreases as temperatures drop, modern heat pumps remain highly efficient—even in cold climates. Today’s advanced heat pumps can deliver up to 2.5 times the heat output for the energy they consume, making them far more efficient than traditional electric resistance heating, even on freezing nights.
But what about the “Emergency Heat” or “Em. Ht.” setting? This feature often causes confusion. Some contractors or well-meaning neighbors might advise switching to this setting during cold weather, but it’s not a good idea. The “Emergency Heat” mode shuts off your heat pump entirely, forcing your system to rely solely on its backup electric coils, which are far less efficient and significantly more expensive to run. Unless your heat pump is not operational, there’s no reason to use this setting.
Instead of toggling on “Emergency Heat,” let your heat pump do its job. If your home feels chilly, gradually raise the thermostat by one or two degrees to improve comfort. Sudden, significant adjustments can unnecessarily activate backup heating, driving up your energy bills. Remember, a properly functioning heat pump can handle the cold without intervention, keeping you warm while saving you money.
How Heat Pumps Work in Cold Weather
Unlike traditional gas or electric furnaces, which create heat by burning fuel or using electric coils, heat pumps transfer heat from one place to another. In cold winter months, an air-source heat pump pulls heat from the outdoor air—even when temperatures are very low—and brings it indoors. Because this process is so efficient, heat pumps can operate for extended periods to keep your home warm while still saving energy.
Ground-source heat pumps, also known as geothermal systems, function similarly to air-source models. However, they gather heat from underground where temperatures are more stable, allowing ground-source systems to maintain exceptional efficiency even during extreme cold. Both types are highly effective and offer unique benefits, but the core principle remains: You can save energy and money by moving heat rather than generating it.
Why Does Your Heat Pump Run Constantly?
Several factors contribute to a heat pump’s longer operating times in cold weather:
- Colder Outdoor Temperatures: Heat pumps provide steady heating rather than the on-and-off cycling typical of a furnace. If temperatures are near or below freezing, the heat pump may need to run constantly to keep up with the demand.
- Energy Efficiency: Heat pumps operate more efficiently when they run continuously at lower speeds rather than cycling on and off. Continuous operation also helps maintain a consistent indoor temperature while minimizing energy spikes.
- Defrost Cycle: During freezing conditions, the outdoor unit may frost. Your heat pump will continue running, but may periodically switch to a defrost cycle to melt the ice.
When to Be Concerned
Although we expect constant operation in cold weather, there are situations where it might signal a problem. Look out for these warning signs:
- No Warm Air Output: If your heat pump is running continuously but blowing cool or lukewarm air, there could be an issue with the refrigerant levels, compressor, or thermostat settings.
- Frozen Outdoor Unit: While a light frost is normal, heavy ice buildup on the outdoor unit can impede performance and indicate a defrost system malfunction.
- Spike in Energy Bills: A sudden, unexplained increase in energy usage might indicate that your heat pump is struggling due to a mechanical problem or poor maintenance.
- Unusual Noises: Grinding, banging, or other strange noises could mean a component is malfunctioning. Address these issues with a technician promptly to prevent further damage.
The Bottom Line
In most cases, it’s normal for a heat pump to run constantly during cold weather. This steady operation is part of its energy-efficient design and ensures your home stays comfortable even when outdoor temperatures plummet. However, it’s worth investigating further if you notice signs of inefficiency or malfunction—such as poor heating, unusual noises, or a frozen outdoor unit.
If you have concerns about your heat pump’s performance, don’t hesitate to contact Precision Comfort Systems. Whether you need routine preventive maintenance, heat pump repairs, or an upgraded system, we’re available 24/7 and on a mission to keep you warm all winter.