Zodiac pool heater displays E09; heater may start but shuts down or may not start at all.

Safety: Gas components must be handled carefully. Turn off gas at the shutoff valve and disconnect power before servicing. If you smell gas, evacuate the area and contact your gas supplier.

• Check wiring to gas valve: Inspect the harness from the ignition/control board to the gas valve. Ensure connectors are tight and wires are not burned or pinched.
• Verify gas supply: Confirm that the manual gas shutoff valve is open and that other gas appliances function normally. Low supply pressure requires a licensed gas technician.
• Listen for valve operation: During a call for heat, you should hear a click from the gas valve when it is energized. No click may indicate a failed coil or no signal from the board.
• Professional testing: Measuring gas valve coil resistance and manifold pressure requires proper tools and training. If E09 persists after basic checks, have a qualified technician test and, if necessary, replace the gas valve with a Zodiac-approved assembly.