E9 318 High

Worcester Bosch E9 318 Fault Code

Also written as E9318 — same fault.

The Worcester Bosch E9 318 fault code means: your boiler has shut down because a safety sensor has detected that the exhaust gases are getting too hot or the sensor itself has lost its electrical connection.. It appears on 9 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: The flue gas temperature sensor contacts have been interrupted
Typical repair cost £120-£250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Worcester Bosch models that show the E9 318 fault code

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

Source

Worcester Bosch E9 318 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