Freezing heat pump: what to do? - Solar Cooling Ecosolaris

Freezing heat pump: what to do?

Freezing heat pump: what to do?

Important Note:

The ECO-SPLIT-12K, ECO-SPLIT-18K, ECO-SPLIT-12K-TROP, and ECO-SPLIT-18K-TROP solar heat pump models are not Cold Climate–rated units.

These units are designed to provide effective heating performance down to approximately -15 °C (5 °F). Below this temperature, performance decreases significantly and proper operation can no longer be guaranteed.

Operating these models at temperatures below -15 °C may result in: 

  • a significant reduction in heating capacity;
  • excessive freezing;
  • more frequent defrost cycles;
  • an increased risk of ice buildup;
  • premature wear of certain components.

Troubleshooting Procedure: Steps to Follow

  1. Check the type of freezing
    • Light, even frost = Normal
    • Thick ice buildup / internal ice / fan frozen in ice → Abnormal = intervention required
  2. Wait for the defrost cycle to start
    • Wait 15 to 30 minutes
    • Check whether:
      • the unit temporarily stops;
      • steam is released;
      • the ice begins to melt.

    If the frost melts: no immediate action required

    If the ice persists: continue with the steps below

  3. Completely clear the outdoor unit
    • Remove snow, ice, leaves, and debris
    • Ensure no wall, fence, or object is blocking airflow
    • Confirm a minimum clearance of 12 to 18 inches (30-45 cm) around the unit
  4. Check drainage
    • Ensure meltwater can drain freely
    • Make sure there is no ice buildup under the unit
    • Verify that the drain pan is not blocked
  5. Check the indoor air filter
    • Clean or replace the filter
    • Ensure indoor airflow is not restricted
  6. If a solid block of ice has already formed
    • Turn off power to the unit
    • Allow the ice to melt naturally
    • Use lukewarm water only to melt the ice
    • Never use hot water
    • Never chip, scrape, or break the ice
  7. Accelerated defrost
    • Set the heat pump to cooling mode
    • Set the temperature below the indoor ambient temperature
    • Let the unit run until the ice has fully melted
  8. Restart and monitor
    • Switch the unit back to heating mode
    • Monitor operation over the next few hours
    • Check whether frost or ice returns quickly

🚫 DO NOT

  • Break or chip the ice
  • Use boiling or very hot water
  • Fully cover the unit
  • Ignore recurring freezing issues

When to Call a Technician

  • Ice returns shortly after defrosting
  • The defrost cycle does not activate
  • The outdoor fan stops or does not operate properly
  • Indoor air becomes lukewarm or cold
  • Unusual noises (grinding, rubbing, clunking)
  • Suspected refrigerant leak
Back to top