PMP
Fafco Solar Pump Relay Fault

Controller shows PMP or PUMP ERROR; solar pump output does not energize.

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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

Burned pump relay contacts on Fafco controller, Loose line or load wiring at pump terminals, Overcurrent damage from oversized pump, Internal controller power supply fault

How to Fix / Troubleshooting

Safety: Turn off power at the breaker and verify with a meter before touching any wiring.

  • Check line voltage: With power on and extreme caution, verify that proper line voltage is present at the controller input terminals.
  • Test relay output: Command solar ON and measure voltage at the pump output terminals. If there is no voltage while the controller indicates the pump should run, the relay is likely failed.
  • Inspect for heat damage: With power off, look for discoloration or burnt marks around the pump relay on the controller board.
  • Verify pump size: Compare the pump's amperage rating to the controller's maximum relay rating. Oversized pumps can weld or burn relay contacts.
  • Replace controller or relay: In most cases, the entire Fafco controller board is replaced rather than the individual relay. After replacement, rewire and test pump operation.
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Repair Difficulty

Hard 4/5

Required Part

Fafco Pump Relay (on Controller Board)
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