Worcester Bosch 326 Fault Code
The Worcester Bosch 326 fault code means: your boiler is struggling to detect the temperature of the water in your separate hot water cylinder, which means it may stop heating your taps or cause the boiler to behave inconsistently.. It appears on 4 Worcester Bosch models in our database.
Technical description: Storage-NTC defect
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 326 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 326 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 12i System manual (PDF)
- Worcester Bosch Greenstar 28CDi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026