BoilerFaultCodesTechnical description
Burning problem – due to the flue line either being blocked or chimney gasket.
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the waste gases are not leaving the property correctly or that fresh air cannot reach the burner. The most common reason is a blockage within the flue pipe or a perished rubber seal that is allowing exhaust gases to leak back into the air intake. When the boiler detects this imbalance, it shuts down immediately to prevent harmful carbon monoxide from entering your home.
This fault can be more common during high winds or extreme weather, which can push debris into the flue or cause pressure fluctuations that trip the safety sensors.
Engineer required
This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.