Vokera c OF Fault Code
Also written as COF — same fault.
The Vokera c OF fault code means: your boiler is currently set to a standby mode where the central heating function has been manually turned off at the controls.. It appears on 1 Vokera model in our database.
Technical description: Heating mode is switched OFF
DIY fix possible
Locate the mode selector or display panel on the front of the boilerPress the heating button or adjust the winter/summer mode setting to enable the central heatingIncrease the temperature setting on your connected room thermostat to trigger a demand for heat
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Gas Safe Register →Vokera models that show the c OF fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera c OF 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