High Lockout
E01 on Ideal Mini S15

Your boiler has tried to start up but cannot light the gas flame, which means your heating and hot water will not work.

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

Ignition failure

What causes this fault?

This fault occurs when the boiler's control system attempts to light a flame but fails to detect one after several attempts. The most common reasons include a lack of gas reaching the burner, a worn-out spark electrode that cannot create a spark, or a faulty internal component failing to signal that the gas is lit.

This fault is more common during extreme cold spells, as external gas meters can sometimes freeze or the gas pressure in the street can drop, preventing the boiler from receiving enough fuel to ignite.

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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