Low
208 on Worcester Bosch Greenstar 1000

Your boiler has been accidentally switched into a testing mode used by engineers to check emissions, which prevents it from heating your home normally.

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

Chimney sweep demand

From this model's manual
Verified against the Worcester Bosch Worcester Bosch Greenstar 1000 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.

What causes this fault?

Maintenance notification

DIY fix possible

Locate the chimney sweep button on your boiler's front control panel.Press and hold the chimney sweep button for approximately 5 seconds.Wait for the display to return to the standard temperature reading and ensure the boiler resumes normal operation.

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