Baxi 皿 neon illuminated Fault Code
Also written as NEONILLUMINATED — same fault.
The Baxi 皿 neon illuminated fault code means: your boiler is simply indicating that it has detected a demand for hot water and is operating normally in hot water mode.. It appears on 6 Baxi models in our database.
Technical description: DHW mode identified
DIY fix possible
Check if a hot water tap is currently turned on somewhere in the houseIf no taps are on, check for a leaking tap or shower headMonitor the light to see if it turns off once all hot water use has stopped
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Gas Safe Register →Baxi models that show the 皿 neon illuminated fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi 皿 neon illuminated fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026