BoilerFaultCodesIdeal H......F........ Fault Code
Also written as HF — same fault.
The Ideal H......F........ fault code means: your boiler has detected a flame when there shouldn't be one, or there is an electrical fault with the sensor that tracks the flame.. It appears on 12 Ideal models in our database.
Technical description: FLAME DETECTION - SHORT CIRCUIT ERROR
What causes the Ideal H......F........ fault?
This fault occurs when the boiler's control system detects an electrical signal for a flame even though the burner should be switched off. The most common reason is a build-up of carbon or moisture on the sensing probe, which creates a false electrical link, or a component failure on the main circuit board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ideal models that show the H......F........ fault code
Click a model for the full fault code list and model-specific repair notes.
- Classic FF 330 Repair: £150-250
- Esprit HE Repair: £120-£280
- Icos Repair: £120-300
- Icos HE Repair: £150-250
- Icos System Repair: £150-300
- Icos System Repair: £120-250
- Isar HE Repair: £150-300
- Isar M30 / M100 Repair: £150-300
- Isar System Repair: £150-300
- Mexico HE Repair: £120-£280
- Mexico Super 100FF / 125FF Repair: £150-300
- Mexico Super 100FF / 125FF Repair: £150-300
Source
Ideal H......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