Ideal Classic NF30–NF80 Fault codes & diagnostics

3 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Regular Natural GasLPG 8.8-23.4 kW 1994-2003 Discontinued

Replaced by: Classic SE

Download the Ideal Classic NF30–NF80 manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Just want the most common Ideal Classic NF30–NF80 faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 3 documented codes

Tap any card for details

Neon I1

Your boiler is failing to start because it detects that the internal fan system is not operating correctly, likely due to a sensor incorrectly reporting air pressure levels before the system has even begun to run.

High Engineer only £150-250

Parts commonly replaced

  • Air pressure switch
  • Fan assembly
  • Venturi

Related codes

Full explanation for Neon I1
Neon I3

Your boiler is receiving power and is currently in its normal standby state, meaning it is ready to fire up whenever you turn on your heating or hot water.

Low DIY-safe

What to check first

  1. No action is required as this is a normal operating status light
  2. Check your thermostat settings if you were expecting the heating to be on
Full explanation for Neon I3
Status & diagnostic codes

3 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

Neon l1 Status Your boiler has detected that the internal fan or air pressure system is sticking in the 'on' position, preventing it from starting its safety checks. Neon l2 Status Your boiler is correctly receiving a signal from the thermostat that the house needs heat, but it has not yet started the ignition process to fire up. Neon l3 Status Your boiler is receiving electrical power and is currently sitting in standby mode waiting for a command to heat up.