High Lockout
E133 on Potterton Promax HE Store

Your boiler is failing to light the gas burner, meaning it cannot provide heating or hot water until the issue is resolved.

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

Interruption Of Gas Supply or Flame Failure / gas supply has been interrupted, ignition has failed or the flame has not been detected

What causes this fault?

This fault occurs when the boiler attempts to ignite but fails to establish or maintain a steady flame. The most common reasons include a lack of gas reaching the unit, a worn-out ignition spark, or a sensor that can no longer detect the flame once it is lit.

This fault is notably common during extreme cold snaps, as the external condensate drainage pipe can freeze and back up, preventing the boiler from lighting.

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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