High
P1, P2, P3, P4... on Worcester Bosch Greenstar i

Your boiler is struggling to start up its internal computer system and may have a blown fuse or a faulty control circuit.

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. Replace fuse S12. Otherwise replace 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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