BoilerFaultCodesYour boiler has detected that the water inside is getting too hot too quickly, usually because there isn't enough water pressure or the water isn't moving through the pipes properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow temperature is higher than the set maximum temperature. Insufficient water. No through flow. Too much air in the system. Deviation in the flow or return temperature sensor.
What causes this fault?
This fault occurs when the heat inside the boiler cannot be carried away by the water quickly enough, causing the system to protect itself from damage. The most common reasons are a lack of water pressure, a blockage in the pipework, or a pump that has failed and stopped moving the water around. It can also happen if too much air is trapped in the boiler, creating an air pocket that stops the flow.
This issue often appears when the heating is turned back on for the first time in autumn, as pumps can seize up after sitting idle over the summer.
DIY fix possible
Check the pressure gauge on the front of the boiler; if it is below 1.0, top it up using the filling loop.Ensure all radiator valves are fully open to allow water to circulate.Bleed your radiators to remove any trapped air that might be blocking the flow.
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A boiler cover plan would cover faults like é1 — no call-out fees, no surprises.
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