BoilerTool
Home
/
Greenstar 27-30 i System
/
b7
b7
Internal error
Worcester Bosch Greenstar 27-30 i System
Cause 257 (Locking)
Internal error. Replace control board.
This code also applies to:
Greenstar CDi Compact Combi
Source:
Manufacturer manual (PDF)
hello@boilertool.co.uk
© 2026 BoilerTool