Heat Pump Not Heating in Winter

Understanding the Problem

Heat pumps work differently than furnaces—they extract heat from outdoor air even when it's cold. However, when outdoor temperatures drop significantly, heat pumps can struggle or may need auxiliary heat to keep up. If your heat pump isn't providing adequate heat, the cause could be as simple as ice buildup or as complex as a refrigerant issue. Understanding how heat pumps work helps diagnose the problem.

Common Symptoms

You might be experiencing this problem if you notice:

• Heat pump runs but house stays cold
• Air from vents is lukewarm or cool
• Heat pump runs constantly but doesn't heat
• Auxiliary/emergency heat running too often
• Outdoor unit covered in ice

Possible Causes

This problem can be caused by several factors, listed from most to least likely:

DIY Troubleshooting Steps

Before calling a professional, try these safe troubleshooting steps:

1. 1

   Check thermostat is set to heat mode

2. 2

   Replace the air filter

3. 3

   Check outdoor unit for ice buildup

4. 4

   Verify outdoor unit fan is running

5. 5

   Test auxiliary/emergency heat switch

6. 6

   Clear snow and debris from outdoor unit

Prevention Tips

Help prevent this issue in the future with these maintenance tips:

• Schedule annual maintenance before winter
• Keep outdoor unit clear of snow and ice
• Change filters monthly in heating season
• Keep auxiliary heat functional as backup
• Consider a hybrid system in cold climates