Zodiac pool heater shows E10; unit may not recognize external controls or may ignore local keypad commands.

Safety: Turn off power before working on low-voltage control wiring.

• Check control mode: On the heater's user interface, verify whether it is set to local control or remote/automation mode according to Zodiac instructions. Incorrect mode can prevent local operation.
• Inspect remote wiring: Open the low-voltage wiring compartment and check the connections to any Zodiac or third-party automation system. Look for shorts between terminals or to ground.
• Temporarily disconnect remote: Remove the remote/automation wires from the heater's control terminals and set the heater to local mode. Restore power and test. If E10 clears, the issue is in the external control system or wiring.
• Check interface board: If present, inspect the communication or interface board for damage or loose connectors. Reseat connectors firmly.
• Replace faulty board: If the heater still shows E10 with all external controls disconnected, the interface or main control board may need replacement.