Low
25:0 on Viessmann Vitodens 100-W / 200-W

Your boiler has lost the connection to the external sensor that tells it how cold it is outside, meaning it may not adjust its heating output as efficiently as usual.

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

No recognition of outside temperature sensor or remote monitoring (only in i).

Engineer required

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

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