Light off Low

Worcester Bosch Light off Fault Code

Also written as LIGHTOFF — same fault.

The Worcester Bosch Light off fault code means: your boiler is currently idle because it hasn't received a signal from your thermostat or programmer to start heating.. It appears on 2 Worcester Bosch models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: No boiler demand
Typical repair cost £0-120 (including labour)

DIY fix possible

Check that your room thermostat is turned up higher than the current room temperatureEnsure your heating programmer or clock is set to an 'ON' periodCheck if the boiler power switch or fused spur is turned on

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Worcester Bosch models that show the Light off fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch Light off 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 7 July 2026