BoilerFaultCodesYour boiler has sensed that the exhaust gases are getting too hot and has shut down as a safety precaution to prevent internal damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: FLUE GAS OVERHEAT
What causes this fault?
This fault occurs when the internal temperature of the exhaust fumes exceeds a safe limit, triggering an emergency shutdown to protect the boiler's components. The most common reason is a build-up of limescale or debris inside the heat exchanger, which prevents heat from being transferred to your water and instead sends it out through the flue. It can also be caused by a faulty sensor giving an incorrect reading or a blockage in the system's circulation.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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