Should I run emergency heat when my heat pump is not keeping up?

Only briefly. Emergency heat runs the electric strips alone and is far more expensive to operate. Use it to stay comfortable until a technician arrives, not as a long-term setting.

Why is my heat pump blowing cool air but not cold?

Heat pump supply air is normally around 90 to 100 degrees, cooler than a gas furnace's. If the house holds temperature, that is expected. If it does not, the charge or auxiliary heat needs checking.

Is ice on the outdoor unit in winter normal?

A light frost between defrost cycles is normal. A solid sheet of ice covering the coil or the fan blades is not, and it usually means a defrost control or sensor failure.

Heat Pump Not Heating in Winter?

Section 1

Normal defrost versus a real fault

Below about 40 degrees, a heat pump periodically reverses to melt frost off the outdoor coil. During that cycle you will see steam off the outdoor unit and feel cooler air inside for a few minutes. That is normal. If the outdoor coil stays iced over for hours, or defrost never runs, the defrost board or sensor has failed.

Section 2

Auxiliary heat that is not coming on

During a hard freeze in Chesnee, Landrum, or Marietta, a heat pump alone cannot always keep up. Electric auxiliary strips are supposed to supplement it. A tripped sequencer, a failed strip, or a miswired thermostat means the system runs continuously and still loses ground. We verify amp draw on each strip rather than assuming from the thermostat display.

Section 3

Refrigerant and reversing valve issues

Heat pumps lose capacity fast when charge is low, and the effect shows up in heating before it shows up in cooling. A reversing valve that fails to shift leaves the system in cooling mode while the thermostat calls for heat, which is why some homeowners report the system blowing cold in December.

Section 4

What to check before calling

Confirm the thermostat is set to Heat and not Emergency Heat, replace a dirty filter, and clear snow, ice, or leaves from around the outdoor unit. Never chip ice off the coil with a tool. If the system still cannot hold temperature after that, it needs gauges and a meter on it.

Frequently asked questions

Should I run emergency heat when my heat pump is not keeping up?: Only briefly. Emergency heat runs the electric strips alone and is far more expensive to operate. Use it to stay comfortable until a technician arrives, not as a long-term setting.
Why is my heat pump blowing cool air but not cold?: Heat pump supply air is normally around 90 to 100 degrees, cooler than a gas furnace's. If the house holds temperature, that is expected. If it does not, the charge or auxiliary heat needs checking.
Is ice on the outdoor unit in winter normal?: A light frost between defrost cycles is normal. A solid sheet of ice covering the coil or the fan blades is not, and it usually means a defrost control or sensor failure.

Services mentioned

Heat Pumps

Repair, maintenance, and replacement for standard, inverter, and dual-fuel heat pump systems.

Heating Repair

Heating and heat pump service when your system is not performing properly.

Emergency HVAC Repair

Urgent heating and cooling failures handled with fast diagnosis and clear options.

heating repair by city

We serve Greenville County, SC and Spartanburg County, SC and Anderson County, SC and Pickens County, SC. Pick your city for local pricing, response times, and scheduling.

Heat Pump Not Heating in Winter: Causes and Fixes