Ideal Neon 3 Fault Code
Also written as NEON3 — same fault.
The Ideal Neon 3 fault code means: your boiler is receiving electrical power and is currently sitting in standby mode waiting for a request to provide heating or hot water.. It appears on 3 Ideal models in our database.
Technical description: Mains electricity ON.
DIY fix possible
Check that your room thermostat is turned up high enough to click onEnsure your programmer or timer is set to an 'ON' periodCheck that the boiler thermostat knob on the front panel is not turned to the 'O' or off position
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Gas Safe Register →Ideal models that show the Neon 3 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal Neon 3 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026