BoilerFaultCodesYour boiler has sensed that the exhaust gases are getting too hot and has shut down as a safety precaution to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flashing lamp, alone or simultaneously with another lamp.
What causes this fault?
This fault occurs when the internal sensor detects that the exhaust gases reaching the flue are dangerously hot. The most common cause is a build-up of debris or limescale inside the main heat exchanger, which prevents heat from being transferred to your water and instead pushes it out through the flue. It can also be triggered by a faulty sensor sending an incorrect reading to the boiler's control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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