BoilerFaultCodesYour boiler has reached an unsafe temperature, causing it to shut down to prevent damage or overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The burner thermostat has been activated.
What causes this fault?
This fault occurs when the water inside the heat exchanger becomes too hot, triggering a safety switch to prevent the unit from melting or exploding. The most common reasons are a failed pump that isn't moving water away quickly enough, or a build-up of sludge and debris that is blocking the flow within the system.
This issue often surfaces when the heating is first turned on after summer, as the internal pump can seize up after months 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 08 — no call-out fees, no surprises.
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