Low
S.0 on Vaillant Ecomax Condensing 600/800 series

Your boiler is currently in standby mode because it is not receiving a request for heat from your thermostat or hot water timer.

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 heat demand (heating operation)

From this model's manual
Verified against the Vaillant Ecomax Condensing 600 800 Series installation & service manual, page 45.
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 your room thermostat is set to a temperature higher than the current room temperature.Ensure your heating programmer or central heating timer is set to 'On'.Check if your hot water cylinder thermostat is calling for heat if you have a traditional tank system.

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