BoilerFaultCodesWorcester Bosch 208 Fault Code
The Worcester Bosch 208 fault code means: your boiler is currently set to a manual testing mode used by engineers to check emissions, which prevents it from operating normally.. It appears on 23 Worcester Bosch models in our database.
Technical description: Chimney sweep demand
What causes the Worcester Bosch 208 fault?
This code appears when the 'Chimney Sweep' mode has been manually activated on the boiler's control panel. It is a setting used by engineers during a service to force the boiler into maximum or minimum output for emissions testing, which overrides your normal heating and hot water settings. If this has appeared unexpectedly, it is usually because the button was pressed by accident or the mode was not exited after a recent service.
This code is frequently seen during the autumn and winter months when annual service visits and safety checks are most commonly scheduled.
DIY fix possible
Locate the 'Chimney Sweep' button (icon looks like a brush) on the touch screen display.Press and hold the button for approximately 3 to 5 seconds.The display should return to the standard temperature screen once the mode is deactivated.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Worcester Bosch models that show the 208 fault code
Click a model for the full fault code list and model-specific repair notes.
- 1000
- 24 RSF
- 26 CDi Xtra Repair: £0-80
- 30i Junior
- 35 RSF Repair: £0-80
- Danesmoor
- GB162
- Greenstar 12i System
- Greenstar 2000
- Greenstar 27CDi
- Greenstar 28CDi
- Greenstar 4000
- Greenstar 8000
- Greenstar 8000 Life
- Greenstar 8000 Life System
- Greenstar 8000 Life/Style
- Greenstar 8000 Style
- Greenstar CDi Compact Repair: £100-200
- Greenstar i
- Heatslave
- Hideaway
- Junior 24i
- Junior 28i Repair: £0-80
Source
Worcester Bosch 208 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026