BoilerFaultCodesVokera 6x Fault Code
Also written as 6X — same fault.
The Vokera 6x fault code means: your boiler has detected a fault with the temperature sensor that controls your hot water, meaning your water may not reach the correct temperature or might not heat up at all.. It appears on 3 Vokera models in our database.
Technical description: Fault codes 6x appear if a problem exists with the secondary (DHW) thermistor.
What causes the Vokera 6x fault?
This fault occurs when the internal sensor responsible for monitoring hot water temperature starts sending incorrect readings or stops communicating with the main control board. The most common reason is that the sensor has suffered from electrical failure or internal corrosion over time, preventing the boiler from knowing how hot the water actually is. As a safety precaution, the boiler stops heating the water to prevent it from becoming dangerously hot.
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 6x fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera 6x 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