Boiler locks out with A02, burner starts then shuts down after a few seconds

Safety: Switch off power and close the gas isolation valve before removing covers. Work on gas components must be done by a licensed technician.

• Check other gas appliances: Confirm that cookers or other gas boilers run without interruption. If they also cut out, contact your gas supplier.
• Inspect flue and air intake: Ensure the concentric flue terminal is clear and firmly connected. A partially blocked flue can cause unstable combustion and flame loss.
• Reset the boiler: Use the reset function and observe whether the boiler runs longer or immediately fails again. Note any unusual noises from the burner.
• Have earthing checked: A qualified electrician or heating engineer should verify that the boiler has a solid earth connection and that the ionisation current is within Wolf specifications.
• Technician tasks: A professional will check ionisation electrode position, clean it if sooted, test gas valve modulation, and verify combustion values.