Medium
db on Viessmann Vitodens 200-W Combi

Your boiler has lost the ability to monitor the temperature in your second heating zone because a sensor has developed an electrical fault.

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 shorted out

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.

What causes this fault?

This fault occurs when the electrical signal from the secondary heating zone's temperature sensor is interrupted by a short circuit. The most common reason is that the delicate internal wiring of the sensor has degraded or has been physically pinched, causing the sensor to send an incorrect electrical reading back to the main control board.

This fault is often noticed at the start of autumn when homeowners first try to turn on their secondary heating zones after the summer break.

Engineer required

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

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Related fault codes

All 87 fault codes on the Vitodens 200-W Combi

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

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