BoilerFaultCodesWorcester Bosch D1241 Fault Code
The Worcester Bosch D1241 fault code means: your boiler has lost its connection to the sensor that monitors the water returning to the unit, causing it to stop working for safety.. It appears on 1 Worcester Bosch model in our database.
Technical description: The contacts of the boiler return temperature sensor have been interrupted
What causes the Worcester Bosch D1241 fault?
This fault occurs when the main control board loses communication with the sensor that monitors the temperature of the water coming back into the boiler. The most common reason is that the sensor itself has developed an internal electrical failure or the wiring connecting it to the brain of the boiler has become loose or damaged.
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 D1241 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch D1241 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