BoilerFaultCodesWorcester Bosch 237 Fault Code
The Worcester Bosch 237 fault code means: your boiler's computer has detected an internal communication error and has shut down as a safety precaution.. It appears on 10 Worcester Bosch models in our database.
Technical description: System fault
What causes the Worcester Bosch 237 fault?
This fault occurs when the boiler's main control board loses the ability to talk to other internal electronic components. It is physically caused by a break in the electrical signal, often due to a loose wiring connection or a component failure on the circuit board itself. Because the 'brain' of the boiler cannot verify that all systems are safe, it shuts down immediately to prevent damage.
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 237 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24/28/35 CDi MkII Repair: £150-250
- Greenstar 1000 Repair: £150-300
- Greenstar 12i System Repair: £150-250
- Greenstar 2000 Repair: £150-300
- Greenstar 27CDi Repair: £150-300
- Greenstar 28CDi Repair: £150-250
- Greenstar 4000 Repair: £150-300
- Greenstar 8000 Life & Style Repair: £150-£450
- Greenstar CDi Compact Repair: £120-250
- Greenstar Heatslave II Repair: £150-300
Source
Worcester Bosch 237 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 1000 manual (PDF)
- Worcester Bosch Greenstar 12i System manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026