Harris pump display shows E11 and stops; often associated with external automation or timer

Safety first: Turn off power to both the pump and any connected automation system before working on control wiring.

• Verify wiring connections: Check the low-voltage terminals on the Harris control module and the external controller. Ensure polarity and terminal assignments match the Harris wiring diagram.
• Test without automation: Disconnect the external control cable and power the pump standalone. If E11 disappears and the pump runs normally, the issue is with the external controller or cable.
• Inspect communication cable: Look for cuts, kinks, or water intrusion in the low-voltage cable. Replace if damaged.
• Check automation settings: Confirm that the external controller is configured for the correct Harris pump model and communication protocol.

If E11 persists even with no external connections, the communication circuitry on the control PCB may be faulty and the module should be replaced.