Worcester Bosch Green/Red - blinking Fault Code
Also written as GREENREDBLINKING — same fault.
The Worcester Bosch Green/Red - blinking fault code means: your boiler has detected that the water pump is struggling to circulate water properly, which could prevent your home from heating up or providing hot water.. It appears on 4 Worcester Bosch models in our database.
Technical description: Warning mode (pump operating in an abnormal condition)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Worcester Bosch models that show the Green/Red - blinking fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch Green/Red - blinking fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
- Worcester Bosch 24/28/35 CDi MkII manual (PDF)
- Worcester Bosch Greenstar 2000 manual (PDF)
- Worcester Bosch Greenstar 27CDi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026