Pump display shows ERR6 and the unit will not start; sometimes accompanied by a faint click from inside the control housing.

Safety first: Disconnect power at the breaker and wait several minutes before opening the control cover.

• Listen for relay operation: With the cover on and power restored, attempt to start the pump and listen for a distinct relay click. No click may indicate a control fault; repeated clicking with no motor movement may indicate stuck contacts.
• Inspect internal connectors: Isolate power again, remove the control cover and check that all spade and plug connectors from the PCB to the motor are fully seated and not heat-damaged.
• Check for moisture: Look for condensation or water inside the control housing. If present, dry the area thoroughly and correct any gland or lid seal issues.

Relay and PCB-level repairs require electronic skills and should be handled by an authorized service center. In most cases the entire control PCB is replaced.