High Lockout
Pilot does not light on Ideal Classic FF

Your boiler is failing to ignite the small starter flame, which means the main burner cannot catch light to provide heating or hot water.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Check gas supply, air in gas line, pilot injector blockage, or supply voltage at pilot gas valve

What causes this fault?

This fault occurs when the small pilot flame fails to ignite or stay lit, preventing the main boiler from firing up. The most common reasons include a buildup of soot or debris blocking the tiny pilot hole, a worn-out probe that can no longer sense the heat, or a lack of gas reaching the burner.

This issue is more common after the boiler has been switched off all summer, as dust can settle in the pilot assembly or the gas line can develop air pockets during periods of inactivity.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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