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Heat Pump Not Heating in Winter? Causes & Fixes

Heat pumps are efficient heating solutions but have unique challenges in cold weather. Understanding how they work helps diagnose issues when your heat pump isn't keeping your home warm.

Signs & Symptoms

!Heat pump blows cool or lukewarm air
!Heat pump covered in ice
!Defrost cycle runs constantly
!Backup/emergency heat always on
!House won't reach set temperature
!Heat pump runs but doesn't heat

Possible Causes

  • -Normal heat pump operation (air feels cooler than furnace)
  • -Defrost cycle stuck or not working
  • -Low refrigerant
  • -Outdoor unit frozen
  • -Reversing valve stuck
  • -Backup heat not working
  • -Dirty coils reducing efficiency
  • -Too cold for heat pump alone

DIY Troubleshooting Steps

Try these steps before calling a professional (unless it's an emergency):

  1. 1Check thermostat settings (heat mode)
  2. 2Verify outdoor unit isn't buried in snow/ice
  3. 3Check air filter
  4. 4Make sure outdoor unit fan is running
  5. 5Check for ice buildup (defrost should clear it)
  6. 6Try emergency heat mode temporarily

When to Call a Professional

  • !Ice buildup that doesn't defrost
  • !System won't maintain temperature
  • !Backup heat isn't working
  • !Strange sounds from outdoor unit
  • !Refrigerant leak suspected
  • !Reversing valve problems

Estimated Repair Costs

Diagnostic: $89-$150

Minor Repair: $200-$500

Major Repair: $600-$2,500

Defrost sensor and refrigerant are moderate repairs. Reversing valve or compressor are major.

Prevention Tips

* Keep outdoor unit clear of snow and debris
* Schedule annual maintenance
* Know when to switch to backup heat
* Clean or replace filters regularly
* Have refrigerant levels checked yearly

Frequently Asked Questions

Why does my heat pump blow cold air sometimes?

Heat pumps blow cool air during defrost cycles (normal, lasts 5-15 minutes) and produce air that's warm but cooler than a furnace. If it's truly cold air constantly, there's a problem needing diagnosis.

At what temperature is a heat pump not effective?

Standard heat pumps lose efficiency below 35-40°F and may need backup heat. Cold-climate heat pumps work down to 0°F or below. In mild Bay Area winters, standard heat pumps usually suffice.

Need Help?

This issue may require emergency service. Call now for immediate assistance.

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Experiencing Heat Pump Not Heating?

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