Low
S.36 on Vaillant ecoTEC System

Your boiler is currently in standby mode because it is not receiving a signal from your thermostat or programmer to turn on the heating.

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

No heating demand from low voltage controls (clamp 7-8-9)

From this model's manual
Verified against the Vaillant Ecotec installation & service manual, page 43.
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

Increase the target temperature on your room thermostat or smart controllerCheck that your heating timer or programmer is set to 'On' at the current timeReplace the batteries in your wireless thermostat controller

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