Low
S.00 on Vaillant ecoTEC plus 612 VU GB 126/3-5

Your boiler is currently on standby and is not receiving a signal from your thermostat or timer to provide heating or hot 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

No heat demand

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus Pro 839592 00 2004 installation & service 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 room thermostat or smart controller to ensure the target temperature is set higher than the current room temperature.Verify that the heating schedule or timer is currently set to an 'on' period.Try turning your heating controls off and on again to reset the connection to the boiler.

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Related fault codes

S.01View →S.02View →S.04View →

All 119 fault codes on the ecoTEC plus 612 VU GB 126/3-5

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

d.00d.01d.02d.03d.05d.06d.07d.08d.09d.10d.11d.17d.18d.19d.22d.23d.25d.26d.30d.33d.34d.35d.36d.40d.41d.44d.47d.50d.51d.60d.61d.64d.65d.67d.68d.69d.70d.71d.72d.73d.75d.76d.77d.78d.80d.81d.82d.83d.84d.90d.91d.93d.97F.00F.01F.02F.10F.11F.13F.20F.22F.23F.24F.27F.28F.29F.32F.60F.61F.62F.63F.64F.65F.70F.71F.72F.73F.74F.75F.76P.1P.2P.3P.4P.5P.6S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.36S.53S.54S.76

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