High Lockout
426 on Ideal Ideal Classic SE15P FF

Your boiler is not receiving enough gas to stay lit safely, which is preventing your heating and hot water from working.

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

Minimum gas pressure

What causes this fault?

This fault occurs when the incoming gas pressure drops below the minimum level required for the boiler to operate safely. The most common reasons are a blockage in the gas supply line, a failing gas valve within the boiler, or an issue with the external regulator on your gas meter.

This issue is more common during extreme cold snaps when high local demand for gas can cause a drop in network pressure, or when external regulators are prone to freezing.

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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