BoilerFaultCodesIdeal Neon3 Fault Code
Also written as NEON3 — same fault.
The Ideal Neon3 fault code means: your boiler has lost power to its main control board, which means the system cannot operate or provide heating and hot water.. It appears on 2 Ideal models in our database.
Technical description: Main supply to PCB 25B.
What causes the Ideal Neon3 fault?
This fault occurs when the link between the boiler's external controls and its internal brain is broken, preventing electricity from reaching the main control board. The most common reason is a component failure on the board itself or a blown internal fuse, which acts as a safety measure if there has been an electrical surge. In some cases, loose or damaged wiring between the components can also stop the power flow.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ideal models that show the Neon3 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal Neon3 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