High Lockout
53 on Ideal Classic FF

Your boiler's small starter flame is lit, but the main burner is failing to ignite because it isn't receiving the gas flow it needs to heat your home.

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

PILOT LIT BUT NO MAINS GAS

What causes this fault?

This fault occurs when the boiler successfully lights its small pilot flame but fails to transfer that flame to the main burner. The most common reason is a mechanical failure within the gas valve or a faulty electronic command from the control board, preventing the main flow of gas from being released. It essentially means the ignition process has started, but the 'full' heat cannot be triggered.

This issue is more frequent during the first cold snap of autumn, as gas valve internal components can seize up after being inactive throughout the summer months.

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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