BoilerFaultCodesWorcester Bosch 1065 Fault Code
The Worcester Bosch 1065 fault code means: your boiler has detected an issue with the sensor that monitors internal water pressure, meaning it cannot confirm if there is enough water to operate safely.. It appears on 5 Worcester Bosch models in our database.
Technical description: System pressure sensor
What causes the Worcester Bosch 1065 fault?
This fault occurs when the boiler's internal computer loses communication with the sensor that tracks water pressure. It is usually caused by a physical failure of the sensor's internal diaphragm or a loose electrical connection in the wiring harness. Because the boiler cannot verify if there is enough water to operate safely without damaging the heat exchanger, it will shut down as a precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the 1065 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 1065 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026