Air Quality

Winter Advisory & Heat Pump Performance

Heat Pumps and Outdoor Temperatures Below 38°

If your home has a heat pump you may notice your home struggling to reach a comfortable temperature when temperatures outside are below 38°

Heat pumps work by pulling in outside air, extracting heat from it and expanding the heat to warm your home. Once outdoor temperatures dip below 38 degrees, especially for multiple days, a heat pump is less capable of generating enough heat to achieve more than 60-65 degree temperatures in the home.

Even with auxiliary or emergency heat strips in the air handler (indoor blower), a heat pump is severely limited when outdoor air temperatures are below 38 degrees.

Feeling Cold air? Heat pumps have a “defrost” mode which switches the heat to AC periodically to heat up the outside coils and allow them to defrost. You may feel non-heated air moving while in the defrost mode.

To avoid overheating or damaging the heat pump, please set your thermostats to 65-67°. If you set your thermostat to an unachievable temperature (over 70°) it can cause the outdoor compressor to run excessively, overheat and shut off. Safety sensors will shut the unit off to allow it to cool down and you’ll be without any heating while its recovering.

By setting the thermostat to 65°, the unit will be able to warm the home for a bit and then the unit will be able to shut off and cool down intermittently. Some heat is better than no heat.

Unit Icing over? Heat pumps “sweat” when operating. Icing of the unit is OK as long as the fan blades are not hitting the ice. The most common cause, obviously, is rain & chilly temperatures. When the temperature dips closer to freezing, you may notice ice accumulating on the coils or refrigerant lines. Depending on your heat pump model, it may offer a defrost cycle that can combat brief freezing periods. The unit can be powered off at the breaker and hosed off if the fan blades are touching the ice or the AC can be turned on briefly to heat up the refrigerant which will also thaw the coil. Return to heating once thawed.

Power Outages? If the unit is not engaging after a power outage, the breakers may need to be reset at the unit level outside. The AC breaker is in the 220v control panel (not the 110v panel).

If your unit does not perform well or recover, give us a call and we’ll schedule a TemperaturePro San Antonio technician to check out your system. (210) 944-TPRO