BoilerFaultCodesWorcester Bosch 258 Fault Code
The Worcester Bosch 258 fault code means: your boiler's internal computer has encountered a software or hardware communication error and has stopped working to protect itself.. It appears on 9 Worcester Bosch models in our database.
Technical description: System fault boiler electronics / basic controller
What causes the Worcester Bosch 258 fault?
This fault occurs when the boiler's internal computer chips fail to talk to each other correctly, leading to a total communication breakdown between the main brain and the control panel. The most common reason is a physical hardware failure on the main circuit board or a corruption in the software that manages the boiler's safety checks.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A cover plan would handle faults like 258: no call-out fees, no surprise bills.
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Worcester Bosch models that show the 258 fault code
Click a model for the full fault code list and model-specific repair notes.
- 24/28/35 CDi MkII Repair: £250-450
- Greenstar 1000 Repair: £200-400
- Greenstar 12i System Repair: £250-450
- Greenstar 2000 Repair: £250-450
- Greenstar 27CDi Repair: £180-350
- Greenstar 28CDi Repair: £180-350
- Greenstar 4000 Repair: £200-450
- Greenstar 8000 Life & Style Repair: £250-£550
- Greenstar CDi Compact Repair: £200-450
Source
Worcester Bosch 258 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