F4
Rheem Compressor Discharge Temperature High / Overheat Protection

Rheem inverter system shows F4 and may not start the compressor; outdoor fan may still run.

Advertisements

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.

Advertisements

Possible Causes

Blocked outdoor coil reducing heat rejection, Overcharged refrigerant system, Non-condensable gases in system, Failed or loose discharge temperature sensor

How to Fix / Troubleshooting

Safety first: Turn off power before cleaning or inspecting the outdoor unit.

  • Clean outdoor coil: Remove debris, leaves, and dirt from the condenser coil. Use a garden hose with gentle pressure from inside out to wash fins. Do not bend fins.
  • Check fan operation: Ensure the outdoor fan starts promptly and runs at full speed. Replace the fan motor if it is slow, noisy, or not starting.
  • Inspect discharge sensor: Confirm the discharge thermistor is properly attached and not heat-damaged. Replace if suspect.
  • Professional check: If F4 persists, a technician should verify refrigerant charge and system pressures and correct any overcharge or restriction.

Warning: Do not attempt to adjust refrigerant charge without proper tools and certification.

Advertisements

Repair Difficulty

Hard 4/5

Required Part

Rheem Outdoor Coil / Discharge Temperature Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements