BoilerFaultCodesVokera Yellow | On permanently Fault Code
Also written as YELLOWONPERMANENTLY — same fault.
The Vokera Yellow | On permanently fault code means: your boiler has detected a problem with the hot water system, meaning you likely have no hot water even if your heating still works.. It appears on 1 Vokera model in our database.
Technical description: DHW fault
What causes the Vokera Yellow | On permanently fault?
This fault occurs when the boiler's internal computer receives an incorrect or missing signal from the temperature sensors responsible for your hot water. The most common reason is that the domestic hot water sensor has failed or become corroded, preventing the boiler from knowing how hot the water is and causing it to shut down the hot water function 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 Yellow | On permanently fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera Yellow | On permanently 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