High Lockout
E10 on Viessmann Vitodens 100-W

Your boiler's internal computer has encountered a software or setting error and can no longer communicate correctly with the system.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Control unit fault. Parameter error.

What causes this fault?

This fault occurs when the boiler's internal memory experiences a corruption or a mismatch in its configuration settings. The most common reason is a physical failure of the main control board or the small electronic 'coding card' that tells the boiler which specific model it is.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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