BoilerFaultCodesYour boiler has sensed that it is getting too hot and has shut itself down to prevent damage or safety issues.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Failed overheat – the overheat thermostat needs checking
What causes this fault?
This fault occurs when the internal temperature of the boiler exceeds safe limits, triggering a safety sensor to cut off the burner. The most common reasons are a pump failure that stops water from circulating, or a blockage within the heat exchanger that prevents heat from being transferred away from the unit.
This issue is more frequent in autumn when heating systems are first turned on after summer, as pumps can seize during long periods of inactivity.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 04 — 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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