Low
Vitodens 222-F on Viessmann A8

Your boiler is operating in a manual or forced constant-temperature mode, usually because it has lost its normal external settings or weather sensors.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Control mode

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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