Worcester Bosch Off (No light) Fault Code
Also written as OFFNOLIGHT — same fault.
The Worcester Bosch Off (No light) fault code means: your boiler is not receiving electrical power or does not realise you are asking for heating or hot water.. It appears on 2 Worcester Bosch models in our database.
Technical description: No demand for heat or appliance is powered off
DIY fix possible
Check if the boiler's power switch is turned onCheck your home's consumer unit (fuse box) to see if a circuit has trippedEnsure your thermostat is turned up and has working batteriesCheck if the external timer or programmer is set to 'On'
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Gas Safe Register →Worcester Bosch models that show the Off (No light) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch Off (No light) 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