BoilerFaultCodesVokera A17 Fault Code
The Vokera A17 fault code means: your boiler has sensed that the water leaving the unit is getting too hot and has shut down as a safety precaution.. It appears on 1 Vokera model in our database.
Technical description: Outlet sensor error for having exceeded the max. outlet temperature
What causes the Vokera A17 fault?
This fault occurs when the boiler's internal safety sensors detect that the water temperature has risen far beyond its safe operating limit. The most common reasons for this are a failing internal pump that isn't moving the hot water away quickly enough, or a faulty sensor that is providing an incorrect heat reading to the control board.
This issue is more common during the first cold snap of autumn when a pump that has been idle all summer suddenly seizes or struggles to circulate water through the heating system.
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 A17 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera A17 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