Low
357 on Worcester Bosch Greenstar i

Your boiler is simply running a routine 100-second self-cleaning cycle to remove trapped air from the system.

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.

From this model's manual
Verified against the Worcester Bosch Greenstar I installation & service manual, page 37.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Wait for the 100-second countdown to complete automatically.Do not turn off or reset the boiler during this time.Check your system pressure once the display returns to normal.

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