BoilerFaultCodesYour boiler has switched itself off for safety because the exhaust gases have reached a temperature that is too high.
Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now — this fault can be dangerous if ignored.
Technical description: Flue overheat
What causes this fault?
This fault occurs when the internal safety sensors detect that the exhaust gases are getting far too hot, which can eventually damage the boiler's components. The most common reasons for this are a build-up of limescale or debris inside the heat exchanger blocking water flow, or a physical blockage within the chimney flue itself. It is a critical safety feature designed to shut the system down before the high temperatures cause a fire risk or melt plastic parts.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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