High Lockout
P2 on Worcester Bosch Greenstar 25 HE Combi

Your boiler is failing to start up because an internal electrical fuse has blown and needs to be replaced.

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

Please wait, initialisation in progress. 24 V fuse blown. Replace fuse.

What causes this fault?

This fault occurs when an electrical surge or a short circuit within the boiler's internal components causes a thin safety fuse to blow. The most common reason is a failing part, such as a multi-way valve or internal sensor, drawing too much power and tripping the fuse to protect the main electronics.

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

P1View →P3View →b1View →

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