BoilerFaultCodesYour boiler has shut down because it has detected that it is getting too hot, tripping a safety switch to prevent damage or danger.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Safety Thermostat Activated (Boiler or Flue)
What causes this fault?
This fault occurs when the water inside the unit reaches an unsafe temperature, triggering a safety switch to kill the power. The most common reasons are a failed pump that isn't moving water away from the heat exchanger fast enough or a buildup of debris causing a blockage in the pipework.
This fault often appears during the first cold spell of autumn when the heating is turned on after being dormant all summer, which can cause internal pump parts to seize.
DIY fix possible
Check that your radiator valves are fully openEnsure there is enough water pressure in the system (typically 1.0 to 1.5 bar on the gauge)Try resetting the boiler by turning the control knob to the 'R' position for five seconds
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A boiler cover plan would cover faults like 7 — 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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