Water heater locks out with E03, fan may not start or stops quickly, no ignition attempt.

Safety: Switch OFF power and close the gas valve before working on the appliance. Risk of carbon monoxide if flue is obstructed.

• Check flue terminal: From outside, inspect the Termet flue terminal for ice, bird nests, leaves, or debris. Clear any obstruction without altering the flue length or slope.
• Inspect condensate trap: On condensing Termet models, locate the condensate trap at the bottom of the heat exchanger. Remove and clean it of sludge and debris, then refill with clean water before refitting.
• Fan operation: Remove the front cover and visually inspect the fan. Spin the impeller gently by hand (power OFF) to ensure it moves freely. Check for broken blades or foreign objects.
• Wiring check: Verify the plug connection from the fan to the main PCB is secure and not corroded.
• Test run: Restore power and demand hot water. Listen for the fan starting. If the fan does not run or is noisy, it likely needs replacement.
• Technician required: Replacement of the Termet flue fan assembly or pressure sensing components should be carried out by a qualified Termet service technician due to combustion safety checks required.