Espa pump controller shows E05 and stops shortly after starting

Safety first: Switch off the pump and relieve pressure using the filter air relief valve before opening any part of the system.

• 1. Check multiport valve: Ensure the filter multiport valve is in the correct position (e.g., FILTER) and not partially between positions. Never move the valve handle with the pump running.
• 2. Inspect return valves: Verify that all return line valves downstream of the Espa pump are open. A closed valve can cause rapid pressure rise.
• 3. Read filter pressure gauge: If the pressure is significantly higher than normal operating pressure, perform a full backwash and rinse cycle to clear the filter media.
• 4. Check for blocked check valve: If a non-return valve is installed on the return line, inspect it for stuck or broken internals that may restrict flow. Clean or replace as needed.
• 5. Restart and monitor: After clearing restrictions, restart the pump and monitor pressure and flow. If E05 persists, the pressure sensor or control PCB in the Espa system may be misreading and require service.