BoilerFaultCodesVokera E 03 Fault Code
Also written as E03 — same fault.
The Vokera E 03 fault code means: your boiler's main internal computer is failing to communicate correctly, which has caused the system to stop working entirely for safety reasons.. It appears on 1 Vokera model in our database.
Technical description: Internal fault (PCB)
What causes the Vokera E 03 fault?
This fault occurs when the boiler's main control board suffers a hardware failure and can no longer process signals from the safety sensors. It is usually caused by electrical components on the circuit board wearing out over time or being damaged by a sudden power surge. Because the 'brain' of the boiler can no longer guarantee safe operation, it shuts the system down entirely.
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 E 03 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera E 03 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