BoilerFaultCodesYour boiler has stopped working because an internal safety sensor has detected that it may be overheating or is unable to verify the water temperature correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: No return signal from LSM (Limit Stat Monitor)
What causes this fault?
This fault occurs when the boiler's safety monitoring system loses communication with the sensor that tracks water temperature. It is usually triggered because a component has failed electrically or the internal wiring has become damaged, preventing the boiler from confirming it is operating at a safe temperature. In some cases, it can also be caused by the boiler actually starting to overheat due to a lack of water circulation.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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