Low
S.31 on Vaillant ecoTEC Pro 30

Your boiler is currently idle because it is set to summer mode or your thermostat is not asking for any 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

Summer mode active or no heat requirement from eBUS controller

From this model's manual
Verified against the Vaillant Ecotec Pro 30 installation & service manual, page 35.
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 external thermostat or boiler control panel to see if the heating is turned off or set to 'Summer' mode.Increase the temperature setting on your room thermostat to see if the boiler activates for central heating.Verify that the heating timer/programmer is currently set to an ON period.

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Related fault codes

S.30View →S.32View →

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