Neon l3 Low

Ideal Neon l3 Fault Code

Also written as NEONL3 — same fault.

The Ideal Neon l3 fault code means: your boiler is receiving electrical power and is currently sitting in standby mode waiting for a command to heat up.. It appears on 2 Ideal models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Mains electricity ON

DIY fix possible

Check that your room thermostat is turned up high enough to trigger a heat demandEnsure your programmer or heating timer is set to 'ON'Check that the boiler temperature control knob is not turned to the 'OFF' position

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Ideal models that show the Neon l3 fault code

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

Source

Ideal Neon l3 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