High Lockout
AC on Worcester Bosch WR325 RSF

Your boiler has lost communication between its internal computer and a key electrical sensor or motor, meaning it cannot operate safely.

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

No electrical connection between component and PCB

What causes this fault?

This fault occurs when the boiler's main control board loses its electrical link with a vital internal component, such as a sensor or the fan motor. It is usually caused by a loose connection, a damaged wiring harness, or a failure within the circuit board itself, preventing the boiler from sending or receiving signals. Because the system can no longer monitor safety or performance, it shuts down to prevent damage.

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 →C6View →E9View →

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