BoilerFaultCodesYour boiler has become too hot and has automatically switched itself off to prevent any damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Boiler exceeds 90°C or faulty thermostat. Reset by pressing the reset button (D)
What causes this fault?
This fault occurs when the water inside the boiler reaches a dangerously high temperature, causing a safety switch to cut the power. The most common reasons are a pump failure that stops water from moving around the system or a build-up of sludge that blocks the heat exchanger. In some cases, the thermostat itself may have simply worn out and is giving a false reading.
This fault often appears during the first cold snap of autumn when a pump that has been sitting idle all summer becomes seized or stuck.
DIY fix possible
Check that all radiator valves are open to allow water to flowAllow the boiler to cool down completelyPress the reset button (D) located on the control panel
Find a Gas Safe engineer
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