Heater displays F09 and will not ignite; may click but no flame appears.

Safety first: Turn off power and do not attempt repeated ignition if you smell gas. Ventilate the area and contact a gas professional if a leak is suspected.

• Check gas shutoff: Verify the external gas shutoff valve to the Thermeau heater is fully open and in line with the pipe.
• Inspect gas valve wiring: With power off, check that the gas valve connector is firmly attached and that wires are not frayed or burned.
• Observe ignition sequence: Restore power and call for heat. Listen for the igniter and then a click from the gas valve. If there is no click, the valve may not be energizing.
• Gas pressure verification: Only a licensed gas technician should connect a manometer to check inlet and manifold pressures against Thermeau specifications.
• Replace gas valve if needed: If the coil is open or the valve fails to open under proper voltage, replace it with the correct Thermeau gas valve assembly.