BoilerFaultCodesIdeal L6 Fault Code
The Ideal L6 fault code means: your boiler thinks a flame is present even though it hasn't been safely ignited, causing the system to shut down for safety.. It appears on 12 Ideal models in our database.
Technical description: False Flame Lockout
What causes the Ideal L6 fault?
This fault occurs when the boiler's internal sensor detects a flame signal at a point in the starting sequence where there shouldn't be one. The most common reason is a faulty flame sensing electrode that is sending a wrong signal to the control board, or a gas valve that is leaking a tiny amount of gas into the burner area before it is supposed to open.
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 L6 fault code
Click a model for the full fault code list and model-specific repair notes.
- Atlantic Combi Repair: £150-250
- Concorde Repair: £120-300
- GB24 / GB30 Repair: £180-350
- i Combi 2 Repair: £120-280
- Instinct2 24 Repair: £120-£350
- Logic Code Combi ESP1 Repair: £120-£250
- Logic Combi C24 C30 C35 Repair: £120-£350
- Logic Combi ESP1 Repair: £120-350
- Logic Max Combi Repair: £120-£250
- Logic+ Repair: £120-350
- Logic+ Heat H Repair: £120-300
- Logic+ System Repair: £120-280
Source
Ideal L6 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 7 July 2026