BoilerFaultCodesVokera b28 Fault Code
Also written as B28 — same fault.
The Vokera b28 fault code means: your boiler has stopped working because the internal fan, which safely clears waste gases, is not spinning or communicating with the main control board.. It appears on 1 Vokera model in our database.
Technical description: No signal from fan
What causes the Vokera b28 fault?
This fault occurs when the boiler's control board sends a command for the fan to start, but detects that the fan isn't spinning at the required speed. The most common reason is the fan motor itself failing after years of use, though it can also be caused by loose electrical connections or a fault on the main circuit board. Because the fan is responsible for safely removing exhaust gases, the boiler will refuse to ignite as a safety precaution.
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 b28 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera b28 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