Medium
D.016 on Vaillant ecoTEC plus System

Your boiler is not receiving the signal from your wall-mounted thermostat to turn on the heating.

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

Roomthermostatstatus(24V)

From this model's manual
Verified against the Vaillant Ecotec Plus installation & service manual, page 73.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check if your room thermostat or smart hub has batteries that need replacing.Ensure the thermostat display is showing and not displaying an error message itself.Turn the thermostat setting up higher than the current room temperature to see if the boiler responds.

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