BoilerFaultCodesVokera 47 Fault Code
The Vokera 47 fault code means: your boiler has sensed that the water returning from your radiators is far too hot, causing the system to shut down to prevent damage.. It appears on 1 Vokera model in our database.
Technical description: When the Return Temperature > 80°C for 5s, the Slave board shuts down
What causes the Vokera 47 fault?
This fault occurs when water is not moving through your heating system fast enough to carry heat away from the boiler, causing it to overheat instantly. The most common reasons are a failed internal pump that isn't pushing the water or a significant blockage within the boiler's heat exchanger. It can also be triggered by a faulty sensor that is incorrectly reporting a high temperature to the control board.
This issue is more common during the first cold spell of autumn when pumps that have been sitting idle all summer tend to seize up.
DIY fix possible
Ensure at least two radiators are fully turned on and not restricted by thermostatic valvesCheck that the internal pump is audible and runningInspect the system pressure gauge and top up to 1.5 bar if it is low
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Vokera models that show the 47 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera 47 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