BoilerFaultCodesVokera 40 Fault Code
The Vokera 40 fault code means: your boiler has detected a temporary internal communication or sensor timing error and is essentially waiting to see if it clears itself.. It appears on 5 Vokera models in our database.
Technical description: Temporary fault code (Refer to section 7.10)
What causes the Vokera 40 fault?
This fault occurs when the boiler's internal electronics detect a brief interruption or a glitch in the data being sent between sensors. The most common cause is a sensor that is starting to wear out or a small electrical disturbance on the main control board that makes the system pause to re-check its readings.
DIY fix possible
Monitor the boiler to see if the code clears automaticallyPress the reset button if the code remains or turns into a lockoutEnsure power to the boiler has not been interrupted or fluctuated
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Vokera models that show the 40 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera 40 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