Low
S.109 on Vaillant ecoTEC plus 424

Your boiler has entered a temporary sleep mode and is currently not heating your home or water.

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

Product'sstandbymodeactivated

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus 610 installation & service manual, page 33.
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 to ensure it is calling for heatPress the 'Reset' button on the boiler control panel onceWait five minutes to see if the system initiates a normal startup sequence

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Boiler cover options

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Related fault codes

S.108View →S.96View →

All 72 fault codes on the ecoTEC plus 424

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

Connectiond.02d.10d.11F.00F.01F.10F.11F.13F.20F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.77F.78F.83F.84F.85F.86F.87F.88F.91P.01S.0S.01S.02S.03S.04S.05S.06S.07S.08S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.39S.42S.46S.53S.54S.88S.91S.96S.98S.99S.108

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