High Lockout
E85739 on Potterton Powermax HE

Your boiler is unable to light the flame because the ignition system is faulty or damaged, leaving you without heating and hot water.

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

Ignition Electrode & leadc/w Gasket & 2 screws

What causes this fault?

This fault occurs when the boiler's spark system fails to create the flame needed to produce heat. The most common reasons are that the ignition electrode has become worn or soot-covered over time, or the high-voltage lead connecting it to the control board has developed a fault.

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.

Find a Gas Safe engineer
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Related fault codes

E01View →E02View →

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