BoilerFaultCodesYour boiler has switched itself off because it became too hot, acting 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: Illuminates if the safety device operates, shutting down the boiler in the event of the system or the boiler overheating.
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature, triggering an automatic shutdown to protect the internal components. The most common reasons are a failed pump that isn't moving water away from the heat exchanger quickly enough, or a blockage within the system pipework. It can also be caused by a faulty sensor incorrectly detecting a high temperature even when the system is actually cool.
This issue often surfaces during the first cold spell of autumn when the heating is turned back on after months of inactivity, which can cause internal pump parts to seize.
DIY fix possible
Allow the boiler to cool down for at least 20 minutesCheck that all radiator valves are open and not blockedPress the reset button or turn the control knob to 'Reset' then back to the desired setting
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A boiler cover plan would cover faults like Boiler Safety Overheat Neon — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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