BoilerFaultCodes.com
E94 High Lockout

Your boiler is struggling to maintain a steady flame because it either isn't receiving enough gas or it is drawing in its own exhaust fumes.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Low gas pressure or exhaust recirculation that could be an issue with gas pressure.

What causes this fault?

This fault occurs when the boiler's flame is unstable or failing to ignite correctly due to an incorrect balance of fuel and air. The most common reasons are a lack of incoming gas pressure from the meter or the boiler accidentally sucking in its own waste exhaust gases through a leak in the flue pipe. This prevents the burner from sustaining a safe, clean flame, causing the system to shut down for safety.

This issue is more frequent during extreme cold spells, as high demand on the local gas network can lead to a drop in pressure at the meter.

Typical repair cost £120-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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