F4
Comfortmaker Compressor Discharge Over-Temperature Protection

Display shows F4 and compressor operation is inhibited or erratic

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Dirty condenser coil, Failed outdoor fan motor, Overcharged refrigerant, Non-condensables in system, Restricted discharge line or condenser

How to Fix / Troubleshooting

Safety: Disconnect power at the outdoor disconnect. Lines may be very hot; allow cooling before contact.

Steps:

  • Clean condenser coil thoroughly: Remove debris and wash coil from inside out.
  • Verify outdoor fan operation: Ensure fan starts immediately with compressor and runs at full speed. Replace fan motor or capacitor if not.
  • Check for airflow obstructions: Maintain clearances around the Comfortmaker unit.
  • Reset: After cleaning and verifying fan, restore power and test.

Technician required: If F4 recurs, a refrigerant or compressor issue is likely and must be addressed by a licensed HVAC technician.

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Repair Difficulty

Hard 4/5

Required Part

Outdoor Fan Motor
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