Low
S.30 on Vaillant ecoTEC Plus 826

Your boiler is currently waiting for a signal from your wall thermostat or smart controller to tell it to turn on the 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

Room thermostat (RT) is blocking heating mode

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus 826 installation & service manual, page 48.
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 that your wall thermostat is set to a temperature higher than the current room temperatureEnsure your thermostat has fresh batteriesCheck your programmer or smart heating app to see if the heating is scheduled to be 'ON' at this time

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Related fault codes

S.31View →S.34View →

All 99 fault codes on the ecoTEC Plus 826

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

F.00F.01F.02F.03F.10F.11F.12F.13F.20F.22F.23F.24F.25F.26F.27F.28F.29F.32F.42F.49F.52F.53F.54F.56F.57F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.80F.81F.83F.84F.85F.90F.91F.92F.93F75P.00P.01P.02P.06S.00S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.31S.32S.34S.39S.40S.41S.42S.46S.53S.54S.57S.58S.61S.62S.63S.76S.96S.97S.98

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