(B) LED turning on High

Ariston (B) LED turning on Fault Code

Also written as BLEDTURNINGON — same fault.

The Ariston (B) LED turning on fault code means: your boiler has tried to ignite to provide heat but failed to detect a flame, causing the system to shut down for safety.. It appears on 2 Ariston models 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: Shutdown due to lighting failure
Typical repair cost £100-280 (including labour)

DIY fix possible

Check that your gas emergency control valve is in the 'on' positionCheck if other gas appliances in your home, such as a hob, are working correctlyPress the 'R' or Reset button on the control panel to attempt a restart

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Ariston models that show the (B) LED turning on fault code

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

Source

Ariston (B) LED turning on fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

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