High Lockout
E2351 on Worcester Bosch CDi Classic

Your boiler has lost its connection to the component that monitors water temperature, meaning it cannot safely heat your home or water until the connection is restored.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Flow temperature sensor disconnected

What causes this fault?

This fault occurs when the boiler's main computer loses electrical communication with the sensor that monitors how hot the water is. The most common reason is that the sensor itself has suffered an internal failure, though it can also be caused by a loose connection or damaged wiring. Because the boiler no longer knows the water temperature, it shuts down as a safety precaution to prevent overheating.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E2 350View →

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