Low
S.30 on Vaillant ecoTEC plus 415 VU 156/6-5

Your boiler is perfectly healthy, but it is currently waiting for a signal from your thermostat to tell it that your home needs more heat.

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

Roomthermostatisblockingheatingmode.

Shared across the ecoTEC plus 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 room thermostat or smart controller settingsIncrease the target temperature on your thermostat to see if the boiler fires upEnsure your thermostat batteries are not flat

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Related fault codes

S.31View →S.33View →

All 72 fault codes on the ecoTEC plus 415 VU 156/6-5

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.31S.32S.34S.39S.42S.46S.53S.54S.88S.91S.96S.98S.99S.108S.109

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