High Lockout
A(5) on Potterton Flamingo RS40 RS50

Your boiler is unable to create the spark needed to light the flame, which means your heating and hot water will not work.

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

Igniter generator not working

What causes this fault?

This fault occurs when the boiler's internal computer sends a signal to start the fire, but no spark is physically generated to ignite the gas. The most common reason is that the electronic ignition component has failed or the spark electrode has become worn or cracked over time. Without this initial spark, the boiler cannot light safely and will shut down to prevent unburnt gas from building up.

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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Related fault codes

A(1)View →A(4)View →

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