BoilerFaultCodesWhat the manual says
Manufacturer manualControls according to 0°C outside temperature: Outside temperature sensor shorted out
From this model's manual
Verified against the Viessmann Vitodens 200 W installation & service manual, page 92.
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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