High Lockout
67:0 to 67:60 on Viessmann Vitodens 333-F

Your boiler has likely detected an internal configuration issue or a fault with the control board that manages your hot water settings.

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

DHW set value adjustable from 0 to 60°C

What causes this fault?

This fault occurs when there is a communication error or a logic mismatch within the boiler's internal computer system regarding hot water temperatures. It is often caused by a failing electronic control board or a corrupted memory module that can no longer process the correct settings for your taps and showers.

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.

Find a Gas Safe engineer
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