High
363 on Worcester Bosch Greenstar 8000

Your boiler is struggling to confirm that the burner flame has safely extinguished before attempting to restart.

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

Ionisation current did not drop during ionisation test

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

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