Low
S. 5 on Vaillant ecoTEC pro 28

Your boiler is currently performing a routine startup check to prepare for heating your home, and this is completely normal behavior.

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

Fan and pump running

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus Pro 839592 05 2006 installation & service manual, page 43.
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

No action is required.Wait a few moments for the boiler to complete its cycle.If the boiler remains in this state for longer than 15 minutes, toggle the power off and on again to clear the temporary hold.

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Related fault codes

S. 0View →S. 1View →S. 2View →S. 3View →S. 4View →

All 135 fault codes on the ecoTEC pro 28

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

3596conConnectionD,11D.0D.1D.2D.3D.4D.5D.7D.8D.9D.10D.12D.13D.17D.18D.20D.22D.23D.25D.27D.28D.30D.33D.34D.35D.40D.41D.44D.47D.50D.51D.60D.61D.64D.65D.67D.68D.69D.70D.71D.72D.75D.76D.77D.78D.80D.81D.82D.83D.84D.90D.91D.93D.96D.97F.0F.1F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.70F.71F.72F.73F.74F.75F.76F.77F.78F70P.0P.1P.2P.3P.4P.5P.6S. 2S.0S.1S.3S.4S.6S.7S.8S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.36S.41S.42S.52S.53S.54S.96S.97S.98

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