Medium Warning
10 on Viessmann Vitodens 200-W

Your boiler is struggling to accurately gauge the weather outside, meaning it might not provide the right amount of heat for your home.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Controls according to 0°C outside temperature: Outside temperature sensor shorted out

What causes this fault?

This fault occurs when the connection to the external weather sensor is broken or damaged, causing a short circuit. The most common reason is water ingress within the sensor housing or a physical break in the thin wiring that runs from the boiler to the outside of your home.

This fault often appears during autumn or winter when heavy rain or frost penetrates the external sensor casing and triggers an electrical short.

Engineer required

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

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