BoilerFaultCodesWorcester Bosch 1075 Fault Code
The Worcester Bosch 1075 fault code means: your boiler has stopped working because it thinks the internal heat sensor is damaged or has an electrical fault, preventing it from monitoring temperature safely.. It appears on 4 Worcester Bosch models in our database.
Technical description: Heat exchanger temp sensor short circuit
What causes the Worcester Bosch 1075 fault?
This fault occurs when the electrical signal from the heat exchanger's temperature sensor reaches an impossible level, usually because the sensor has failed internally. The most common reason is that the sensor has developed a short circuit, meaning it can no longer accurately tell the boiler how hot the water is, causing the system to shut down for safety.
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 1075 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 1075 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 Greenstar 2000 manual (PDF)
- Worcester Bosch Greenstar 27CDi manual (PDF)
- Worcester Bosch Greenstar 4000 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026