Low
131 on Worcester Bosch Greenstar CDi Compact

Your boiler has detected a new smart control or accessory and is currently struggling to communicate with it, meaning it needs help to recognize the new connection.

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

Fault 11 System configuration: new BUS device: New ISM detected

From this model's manual
Verified against the Worcester Bosch Greenstar Cdi Compact installation & service manual.
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

Switch the boiler off at the mains power supplyWait for at least 60 seconds to allow the internal memory to resetSwitch the power back on and wait for the boiler to automatically re-scan for connected devices

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