Low Service
Slow flashing reset button on Worcester Bosch Greenstar 12i System

Your boiler is working normally, but it is providing a friendly reminder that its annual safety and maintenance service is now due.

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.

Technical description

The appliance has a service reminder - please contact your service engineer.

What causes this fault?

This is not a mechanical failure, but a timer-based notification triggered by the control board. It occurs because the boiler has reached a specific interval of internal operating hours or a set calendar date since its last professional inspection. The system uses this feature to ensure the appliance continues to run safely and efficiently by prompting a scheduled check-up.

DIY fix possible

Check your service records to see when the last professional service was carried outContact a Gas Safe registered engineer to book an annual service and safety checkOnce serviced, the engineer will reset the reminder timer for you

Find a Gas Safe engineer
Search the official register →

Related fault codes

H13View →

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