Poolex pool heater displays E4 and shuts down; may be accompanied by loud compressor noise.
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: High temperatures and pressures are involved. Turn off power and do not repeatedly reset the unit.
User checks:
- Clean coils and ensure airflow: Remove debris and ensure clearances around the unit.
- Verify water flow: Confirm strong water flow through the Poolex heater.
- Allow cool-down: Let the unit sit powered off for at least 30–60 minutes, then restart.
If E4 returns quickly, a technician should check refrigerant charge, compressor current, and the compressor thermal sensor. Continued operation with E4 can permanently damage the compressor.
Repair Difficulty
Required Part
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