Low
357 on Worcester Bosch Greenstar 12i System

Your boiler is currently running an automated self-cleaning cycle to remove air from its internal pipes, which is a normal process that will finish on its own in less than two minutes.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Appliance in air purge mode. Primary Heat Exchanger air venting program active - approximately 100 seconds (only available when using the optional integral diverter valve kit).

From this model's manual
Verified against the Worcester Bosch Greenstar 12i System installation & service manual, page 64.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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