High Lockout
G2 on Worcester Bosch WR325 RSF

Your boiler has detected an issue with the cold water arriving at the unit, meaning it cannot safely heat water for your taps or shower.

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

Cold water fault inlet pipe

What causes this fault?

This fault occurs when the boiler cannot detect a consistent flow or pressure of cold water entering the system. The most common reason is a blockage caused by grit or debris in the inlet filter, or a mechanical failure of the internal turbine that monitors water movement.

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

A7View →

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