BoilerFaultCodesWorcester Bosch 1023 Fault Code
The Worcester Bosch 1023 fault code means: your boiler has been running for a long continuous period and needs to be reset to ensure its internal monitors can perform a safety self-check.. It appears on 8 Worcester Bosch models in our database.
Technical description: Maximum run time including standby time reached
What causes the Worcester Bosch 1023 fault?
This fault occurs when the boiler has been powered on for a very long duration without a break, causing it to reach its programmed software limit for continuous operation. It happens because the system needs to briefly power down and restart to perform essential internal safety tests and recalibrate its sensors. A simple manual reset allows the boiler to complete these checks and return to normal operation.
This code is slightly more common in winter when boilers are under heavy demand and running constantly to maintain home heating without reaching their standby state.
DIY fix possible
Locate the 'Reset' button on the boiler control panel.Press the reset button once.The boiler should restart and resume normal operation.
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Gas Safe Register →Worcester Bosch models that show the 1023 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 1023 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