High
FAIL POINT J on Worcester Bosch Greenstar 25Si

Your boiler is struggling to breathe because it cannot clear out exhaust gases properly, so it has safely shut itself down to prevent any issues.

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

Air Pressure Fault: Fan failure, air pressure switch shorting, pressure switch not closing (venturi/tube blockage), or flue restriction.

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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