BoilerFaultCodesVokera 28 Fault Code
The Vokera 28 fault code means: your boiler has detected that the water is not circulating correctly between the heating system and the boiler, which has caused it to shut down to prevent damage.. It appears on 5 Vokera models in our database.
Technical description: flow/return ∆T error
What causes the Vokera 28 fault?
This fault occurs when the boiler's internal computer system experiences a temporary glitch in communication between its electronic components. It is most commonly caused by a minor electrical interference or a momentary loss of data signal, which prompts the boiler to automatically reset to ensure everything is working correctly.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Vokera models that show the 28 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera 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 7 July 2026