Blue light off High

Worcester Bosch Blue light off Fault Code

Also written as BLUELIGHTOFF — same fault.

The Worcester Bosch Blue light off fault code means: your boiler currently has no power, which means it cannot provide hot water or heating until the electrical connection is restored.. It appears on 3 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: External control or internal frost thermostat is not calling for heat, or No power to the boiler / Internal fuse blown
Typical repair cost £100-250 (including labour)

DIY fix possible

Check that the main boiler power switch, the fused spur, and the thermostat are all switched on.Check your home's main fuse box (consumer unit) to see if a circuit breaker has tripped.If the boiler still has no power after checking your home's electrics, a qualified engineer should be called.

Find a Gas Safe engineer

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Worcester Bosch models that show the Blue light off fault code

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

Source

Worcester Bosch Blue 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 27 April 2026