Heat PumpTroubleshooting2026-01-16
Heat Pump Frozen or Iced Up: What to Do
Some frost is normal; a fully iced outdoor unit that won't defrost signals a problem.
Heat pumps frost up in cold, damp weather and defrost automatically. Persistent, heavy ice means something needs attention.
Normal vs problem icing
A light coating of frost that clears during the defrost cycle is normal. A thick block of ice covering the coil that doesn't melt indicates a defrost fault, low refrigerant, or airflow problem.
What to do
Make sure nothing blocks airflow and the unit drains freely. Don't chip ice off with sharp tools. If heavy ice persists, switch to backup heat and call for service.
Key takeaways
- Light frost is normal; solid ice is not
- Keep the outdoor unit clear and draining
- Never chip ice off the coil
- Persistent icing needs a technician
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Licensed, gas-certified technicians serving Greater Vancouver since 1999. CombiBoiler.ca — A division of ROMA Heating Ltd..
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