How much does it cost to fix Ideal error code L F (flashing)?

Typical repair cost for the Ideal L F (flashing) fault is £150-350 including labour.

L F (flashing) High

Ideal L F (flashing) Fault Code

Q: What does the Ideal L F (flashing) fault code mean?

Your boiler is failing to light the gas flame after three attempts, which means it has safely shut itself down to prevent a build-up of unburnt gas.

Also written as LFFLASHING — same fault.

The Ideal L F (flashing) fault code means: your boiler is failing to light the gas flame after three attempts, which means it has safely shut itself down to prevent a build-up of unburnt gas.. It appears on 2 Ideal models in our database.

Technical description: Boiler is not working for central heating or hot water but attempts to fire by going through 3 ignition attempts.

Typical repair cost £150-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Ideal models that show the L F (flashing) fault code

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

Source

Ideal L F (flashing) 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