BoilerFaultCodesYour boiler has shut down because it has detected that it is getting too hot, triggering a safety switch to prevent damage.
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 alarm indicator
What causes this fault?
This fault occurs when the water inside the heat exchanger exceeds a safe temperature limit, causing the safety thermostat to cut power to the burner. The most common reasons are a lack of water flow caused by a failing pump, a blockage in the system, or a faulty sensor that is incorrectly reporting the temperature.
This fault is more common in winter when heating systems are under the most strain or when cold-start demands are at their highest.
DIY fix possible
Check that your radiator valves are open and not turned to zeroEnsure there is enough pressure in the system (typically between 1 and 1.5 bar on the gauge)Wait for the boiler to cool down and press the reset button
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like VA-TS — 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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