BoilerFaultCodesVokera b 28 Fault Code
Also written as B28 — same fault.
The Vokera b 28 fault code means: your boiler has stopped working because it cannot communicate with the internal motor that clears out exhaust gases.. It appears on 1 Vokera model in our database.
Technical description: No signal from fan
What causes the Vokera b 28 fault?
This fault occurs when the boiler's control board cannot detect any movement from the internal fan, which is essential for clearing dangerous exhaust fumes. The most common reason is a mechanical failure within the fan motor or a communication break in the electrical wiring connecting the fan to the main computer. In some cases, the fan may be physically blocked by debris or the control board itself may have stopped sending power to the component.
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 b 28 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera b 28 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