F- High

Ideal F- Fault Code

Also written as F — same fault.

The Ideal F- fault code means: your boiler has stopped working because it has detected a specific internal problem, which it will show by alternating the 'f' with another number or letter.. It appears on 3 Ideal models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Boiler is in lockout for a specific error. Display will be blinking, alternating with a number or letter to show which error is detected.
Typical repair cost £80-350 (including labour)

DIY fix possible

Wait for the display to flash the number or letter following the 'F' to identify the specific fault.Try resetting the boiler by turning the mode knob to 'Reset' for two seconds and then back to the original setting.Check that your gas supply is active and your prepaid meter (if applicable) has credit.

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Ideal models that show the F- fault code

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

Source

Ideal F- 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