18 Emergency

Vokera 18 Fault Code

The Vokera 18 fault code means: your boiler has detected that the water pressure inside the system is dangerously high, causing a pressure relief valve to activate to prevent damage.. It appears on 2 Vokera models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Safety Valve fault
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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Vokera models that show the 18 fault code

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

Source

Vokera 18 fault code information on this page is sourced and cross-checked against the official Vokera service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026