High Lockout
Fault 56 147 on Worcester Bosch Greenstar CDi Compact

Your boiler's internal pump has been left in a manual testing mode, meaning it isn't responding correctly to your heating demands.

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

Pump (SP) in manual mode.

What causes this fault?

This fault occurs when the boiler's internal pump has been manually set to a constant test speed, preventing it from automatically adjusting based on your heating needs. It is usually caused by an engineer accidentally leaving the pump in diagnostic mode after a service or a temporary software glitch in the control board.

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

224View →C6View →

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