Poolex pool heater shows F8 and stops; fan may run but compressor does not.
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.
Possible Causes
How to Fix / Troubleshooting
Safety: Turn off power before servicing. High temperatures and pressures are involved.
User-level checks:
- Clean air coil: Remove debris from the coil surfaces and ensure at least the recommended clearance around the unit.
- Verify water flow: Confirm that the pool pump is running and that filters and strainers are clean.
- Check ambient temperature: Extremely high ambient temperatures can cause F8; operate the unit during cooler parts of the day if possible.
Sensor inspection:
- Locate the discharge temperature sensor on the compressor discharge line (small copper tube leaving the compressor).
- Ensure the sensor is firmly attached and insulated as originally installed.
- Inspect wiring for damage and reseat connectors.
If F8 recurs, a technician should measure discharge temperature and pressures, test the discharge sensor, and evaluate compressor health. Do not bypass safety sensors.
Repair Difficulty
Required Part
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