BoilerFaultCodesYour boiler has detected that the water inside the system is getting too hot and has shut down as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Excessive temperature on primary circuit
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, triggering a safety shut-off to protect the internal components. The most common reasons are a failed pump failing to move water away from the heat exchanger, a blockage in the pipework, or a faulty sensor incorrectly reading the temperature.
This issue often surfaces when the heating is first turned on after summer, as pump components can seize up during long periods of inactivity.
DIY fix possible
Check that your radiator valves are openEnsure there is enough water pressure on the boiler's gauge (usually 1.0 to 1.5 bar)Turn the boiler off and on again to try a reset
Find a Gas Safe engineer
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