Low
S.36 on Vaillant Ecomax Condensing 600/800 series

Your boiler is currently in standby mode because it is not receiving a signal from your thermostat or timer 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

No heating demand from low voltage controls

From this model's manual
Verified against the Vaillant/Vaillant Ecomax installation & service manual, page 45.
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 and set it to a temperature higher than the current room temperatureEnsure your programmer or heating timer is set to the 'ON' position for the current timeCheck if any external smart heating controls or apps require a reboot or are showing a connection error

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Related fault codes

S.30View →

All 90 fault codes on the Ecomax Condensing 600/800 series

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

d.0d.1d.2d.5d.7d.8d.10d.11d.13d.14d.16d.22d.23d.24d.25d.34d.35d.40d.41d.44d.46d.47d.60d.61d.67d.68d.69d.71d.72d.73d.80d.81d.82d.83F.0F.1F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.60F.61F.62F.63F.64F.65F.67P.1P.2P.5S.0S.1S.2S.3S.4S.5S.6S.7S.8S.10S.11S.13S.14S.15S.16S.17S.20S.21S.23S.24S.25S.26S.27S.28S.30S.32S.34S.37S.39S.53S.54

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