Poolex pool heater displays Fd and will not start; often after incorrect wiring or power issues.
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: Only qualified personnel should work on three-phase electrical systems. Turn off and lock out power before inspection.
Checks:
- Verify all phases present: An electrician should measure voltage between all three phases at the Poolex terminal block.
- Check rotation: If the unit indicates phase sequence error, swap any two phases at the supply terminals to correct rotation.
- Tighten terminals: Inspect and tighten all phase and earth connections.
If Fd persists with correct phase and voltage, the internal phase monitor or main control board may be faulty and require replacement.
Repair Difficulty
Required Part
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