Worcester Bosch Double flash Blue light Fault Code
Also written as DOUBLEFLASHBLUELIGHT — same fault.
The Worcester Bosch Double flash Blue light fault code means: your boiler has automatically turned itself off because the exhaust area is getting too hot, indicating a potential blockage or a problem with how the gases are clearing.. It appears on 1 Worcester Bosch model in our database.
Technical description: Flue overheat sensor has exceeded 105°C
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 Double flash Blue light fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch Double flash Blue 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