De-Icing a Frozen HVAC Unit SOP

De-Icing a Frozen HVAC Unit SOP

Purpose:
If an HVAC system is found to be frozen upon arrival, follow the steps below to safely de-ice/thaw the system before proceeding with diagnostics.

Warning
Do NOT instruct the customer to leave the system 
off with fan running and return later. De-ice on-site.

1. Billable Demands & Warranty Calls

  • Billable Calls:
    Offer a De-Icing option based on location of ice buildup:
    • Indoor Coil: T600995 – 0.5
    • Outdoor Coil/Compressor: T600996 – 0.5
  • Warranty Calls:
    Proceed directly to Step 2.

2. De-Icing Procedures
A. Indoor Coil De-Icing
Warning
Always confirm condensate line/pump is clear to drain water.
Document and notify the customer of any existing water damage.

    1. Heat Pump Systems

      1. Remove air filter.
      2. Set thermostat to HEAT (not Emergency/Aux).
      3. Run heat for 5–10 min or until ice sheet/block separate from coil.
      4. Outdoor unit may shut off on high head pressure → set blower fan to ON while waiting for reset.

    1. Gas Furnace Systems

      1. Remove air filter.
      2. Remove evap coil access panel and delta plate (if possible).
      3. Set thermostat to HEAT and run for 5–10 min or until ice sheet/block separate from coil.
      4. Furnace may shut off on high limit → set blower fan to ON, wait 5 min, then power cycle to reset.

B. Outdoor Coil/Compressor De-Icing

    1. Remove air filter.
    2. Set thermostat to Fan/Blower ON only.
    3. Spray outdoor coil/compressor with water from garden hose until all visible ice has thawed 

3. Manual Ice Removal

  • Carefully remove large sheets/blocks of ice from coils by hand.
  • Do NOT use sharp tools (risk of coil damage).

4. Restore & Diagnose

  • Return thermostat, fan, and system to normal settings.
  • Continue with full diagnostic to identify root cause of freeze-up.


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