Low
S.31 on Vaillant ecoFIT Pure 412

Your boiler is perfectly healthy and is currently waiting for a signal from your thermostat 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: Summer mode, eBUS controller, waiting period

Shared across the ecoFIT Pure range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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 thermostat or programmer settingsTurn up the target temperature on your room thermostatEnsure the heating timer is currently set to the 'on' period

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Related fault codes

S.30View →S.34View →

All 74 fault codes on the ecoFIT Pure 412

Seeing a different code? Every code this model can display, in one place.

cond.02F.00F.01F.10F.11F.13F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.76F.77F.83F.85F.87F.88F.89P.00P.01P.02P.06S.0S.01S.02S.03S.04S.05S.06S.07S.08S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.32S.34S.39S.42S.46S.53S.54S.88S.91S.96S.98S.99S.108S.109

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