Safety: Shut off power at the breaker before working on the circulation system.

Verify water level and filters: Ensure proper water level and clean all Villeroy & Boch filters. Dirty filters can starve the circulation pump.
Check for air lock: With power off, loosen the union on the circulation pump until water seeps out and air escapes, then retighten. This helps purge trapped air.
Observe pump operation: Restore power and watch the circulation pump. It should run quietly and continuously. If it hums, overheats, or stops after a few seconds, it may be failing.
Inspect intake screens: Check the suction fittings and any dedicated circulation intake in the spa shell for debris or blockages.
Check electrical connections: With power off, confirm that the circulation pump plug is fully seated in the Villeroy & Boch control pack and that there are no signs of burning or corrosion.

If F5 persists and the pump is not running smoothly, replacement of the circulation pump assembly is typically required.

F5 displayed, circulation pump does not run or runs intermittently

Possible Causes