Low
dE on Viessmann Vitodens 222-F

Your boiler is currently operating on a fixed schedule and is ignoring temperature adjustments from your room thermostat or smart controller.

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.

What the manual says

Manufacturer manual

Control mode without room influence

From this model's manual
Verified against the Viessmann Vitodens 222 F installation & service manual, page 96.
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 boiler's control system can no longer detect a signal from the temperature sensor assigned to your second heating zone. It is usually caused by a loose electrical connection, a break in the thin sensor wiring, or the internal component of the sensor failing due to age.

Engineer required

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

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Related fault codes

dEView →bCView →

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