BoilerFaultCodesWorcester Bosch EE6 Fault Code
The Worcester Bosch EE6 fault code means: your boiler has detected an issue with the external valve system, preventing it from operating correctly and resulting in a total loss of heating and hot water.. It appears on 1 Worcester Bosch model in our database.
Technical description: External valve
What causes the Worcester Bosch EE6 fault?
This fault occurs when the boiler is unable to communicate with or operate the external valves that direct water to your radiators or hot water cylinder. The most common cause is a mechanical failure in the motorised valve head or a loose connection within the wiring center that manages your heating controls.
This fault is more frequent in autumn when heating systems are switched back on after a long summer break, often causing internal valve components to seize.
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 EE6 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch EE6 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