Heater shows E10; keypad or external controller does not respond properly

Safety: Turn off power before working on low-voltage wiring to avoid damaging electronics.

• Check local control first: If using an external pool controller, switch the SunHeater to Stand-Alone or Local mode (if available) and see if the heater operates normally from its own keypad. This helps isolate the problem.
• Inspect communication wiring: Locate the low-voltage terminal strip on the main control board. Tighten any loose screws and look for corrosion. Clean with contact cleaner if needed.
• Test cable continuity: If a separate communication cable runs to a wall-mounted display or automation panel, disconnect both ends and test each conductor for continuity and shorts. Replace the cable if damaged.
• Check dip switch / configuration: Verify that any communication mode dip switches on the SunHeater control board are set correctly for your automation system.
• Replace UI board if needed: If the local keypad is unresponsive or displays garbled characters along with E10, the Display/Keypad Board may be defective and require replacement.