BoilerFaultCodesVokera b26 Fault Code
Also written as B26 — same fault.
The Vokera b26 fault code means: your boiler has stopped working because the waste water pipe or trap is full and cannot drain away properly.. It appears on 1 Vokera model in our database.
Technical description: Condensate trap blocked
What causes the Vokera b26 fault?
This fault occurs when the internal reservoir that collects waste water becomes full and cannot empty into your drains. The most common reason is a physical blockage caused by a buildup of debris within the plastic trap or a restriction in the external pipework. To prevent flooding and potential damage to the burner, a safety float switch triggers and shuts the boiler down automatically.
This fault is significantly more common during freezing winter temperatures, as the external waste pipe can freeze solid and prevent water from leaving the system.
DIY fix possible
Locate the white plastic condensate pipe leading away from the boiler.If the pipe runs outside, check if the end is frozen and pour warm (not boiling) water over it to melt any ice.Check for any obvious kinks or blockages in the visible sections of the plastic drainage pipe.
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Gas Safe Register →Vokera models that show the b26 fault code
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Source
Vokera b26 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