BoilerFaultCodesViessmann E0 Fault Code
The Viessmann E0 fault code means: your boiler has shut down because an external safety device, such as a thermostat or water pressure switch, has detected a potential issue and stopped the burner from firing.. It appears on 1 Viessmann model in our database.
Technical description: Burner blocked, fault in the external safety chain
What causes the Viessmann E0 fault?
This fault occurs when an additional safety device outside the boiler's main control board breaks the electrical circuit to prevent damage. It is usually triggered by a secondary sensor detecting that the system pressure is too low or that the water temperature has exceeded a safe limit. Essentially, an external 'shout' has told the boiler to stop firing for your safety.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Viessmann models that show the E0 fault code
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Source
Viessmann E0 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026