Low
S.30 on Vaillant ecoTEC plus aquaPLUS

Your boiler is working fine, but your thermostat or programmer is not telling it to turn the heating on.

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 external controls

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus installation & service manual, page 38.
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 is set higher than the current room temperature.Replace the batteries in your wireless thermostat or programmer.Ensure your heating timer or external controller is set to 'ON' or 'AUTO'.

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