BoilerFaultCodesVokera E08 Fault Code
The Vokera E08 fault code means: your boiler has stopped working because one of its internal temperature sensors has developed a fault and can no longer monitor the water returning to the unit.. It appears on 6 Vokera models in our database.
Technical description: Return thermistor fault
What causes the Vokera E08 fault?
This fault occurs when the sensor responsible for measuring the temperature of the water flowing back into the boiler fails or sends an unreadable signal to the main control board. The most common reason is that the internal components of the thermistor have degraded over time, though it can also be caused by loose or damaged electrical connections. Since the boiler can no longer safely monitor its own temperature, it shuts down to prevent overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Vokera models that show the E08 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera E08 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 27 April 2026