Medium
dE on Viessmann Vitodens 300-W

Your boiler has lost connection with the sensor that monitors the temperature for your second heating zone, meaning it cannot accurately heat that specific area of your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Heating circuit M2 room temperature sensor lead break

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 200 W installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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All 60 fault codes on the Vitodens 300-W

Seeing a different code? Every code this model can display, in one place.

0F9A9b9C9F101820283038404850515858:05980:092939497:2A2:0A7b0b1b4b5b7b8bAbCbdbEbFC2C5C6C7CdCECFdAdbE4E5E6F0F1F2F3F4F7F8F9FAFdFE

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