High
Lock state on Biasi Prisma

Your boiler has shut down completely for safety because it failed to light or stay lit after several attempts.

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.

What the manual says

Manufacturer manual

The ignition device can lock the functioning of the boiler and stop its functioning up to the resetting intervention. The lock is signalled by the ignition of the lock lamp.

From this model's manual
Verified against the Biasi Prisma installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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