BoilerFaultCodesYour boiler has shut down because it is getting too hot inside, likely due to water not flowing properly through the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: OVERHEATING LOOP: PUMP BLOCKED OR ITS CONDENSER OUT OF SERVICE. ISOLATING COCKS CLOSED ON JIG. DEFECTIVE OVERHEAT THERMOSTAT. BLEED OUT AIR. CHECK THE ELECTRICAL CONNECTIONS.
What causes this fault?
This fault occurs when water cannot circulate through the boiler quickly enough to carry heat away, causing the internal temperature to reach a dangerous level. The most common reasons are a seized internal pump that has stopped spinning or a blockage within the pipework, such as trapped air or closed valves. This trigger is a safety mechanism designed to protect the boiler's internal components from heat damage.
This issue often appears when the heating is first turned on after summer, as pumps can seize up due to long periods of inactivity.
DIY fix possible
Check that all valves (isolating cocks) underneath the boiler are in the open position.Bled all your radiators to ensure there is no trapped air in the system.Ensure the boiler pressure is topped up to between 1 and 1.5 bar.
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A boiler cover plan would cover faults like 05 — 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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