BoilerFaultCodesYour boiler has got too hot and has automatically shut down 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: Overheat thermostat operated or faulty. Allow to cool. Check continuity across thermostat terminals.
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature, triggering a safety switch to kill the flame. The most common reasons are a pump failure preventing heat from being carried away or a build-up of sludge and debris blocking the internal pipework.
This fault is more common in autumn when heating systems are first turned back on, as pumps can seize up after being inactive throughout the summer.
DIY fix possible
Ensure all radiator valves are fully open to allow water to circulate.Let the boiler cool down for 30 minutes.Turn the control knob to the 'Reset' position for five seconds, then turn it back to 'On'.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like Section J (Neon Flashing) — no call-out fees, no surprises.
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Potterton Performa System HE is discontinued — time for a new one?
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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