High
Red L.E.D. B on Ariston Microsystem 15

Your boiler has stopped working because it failed to light the flame, which usually happens due to a gas supply issue or a temporary glitch.

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

SHUTDOWN DUE TO THE FAILURE OF THE BURNER TO LIGHT AUTOMATICALLY. This anomaly is indicated by the red “B” L.E.D. To reset the unit, press and then release the “A” button.

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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