All Lamps ON High

Biasi All Lamps ON Fault Code

Also written as ALLLAMPSON — same fault.

The Biasi All Lamps ON fault code means: your boiler's internal computer has suffered a critical failure and can no longer control the heating or hot water functions.. It appears on 1 Biasi model in our database.

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: Faulty electronic control p.c.b.
Typical repair cost £250-£400 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Biasi models that show the All Lamps ON fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Biasi All Lamps ON fault code information on this page is sourced and cross-checked against the official Biasi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026