Biasi A fault on gas supply Fault Code
Also written as AFAULTONGASSUPPLY — same fault.
The Biasi A fault on gas supply fault code means: your boiler has stopped working because it cannot detect a steady supply of gas or a flame.. It appears on 1 Biasi model in our database.
Technical description: Boiler lock state cause.
DIY fix possible
Check if other gas appliances, like a cooker, are working to confirm gas supply to the house.Verify that your gas meter has credit if it is a pre-payment type.Locate the reset knob on the front panel and turn it to the 'R' position for a few seconds.
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Gas Safe Register →Biasi models that show the A fault on gas supply fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Biasi A fault on gas supply 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 27 April 2026