Low
S.36 on Vaillant ecoTEC exclusive 835 VUW 356/5-7

Your boiler has temporarily blocked heating mode because the room thermostat or smart controller is currently set to an invalidly low temperature.

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

Reference setting for continuous controller 7-8-9 or eBUS controller is < 20°C and blocks the heating mode

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Exclusive 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

Locate your main room thermostat or smart heating controller (such as a Vaillant vSMART or eBUS control).Check the current target temperature setting on the display.Increase the temperature setting above 20°C to lift the heating block.

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Related fault codes

S.34View →S.35View →

All 207 fault codes on the ecoTEC exclusive 835 VUW 356/5-7

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

conF.00F.00F.01F.01F.02F.02F.03F.03F.10F.10F.11F.11F.12F.12F.13F.13F.20F.20F.22F.22F.23F.23F.24F.24F.25F.25F.26F.26F.27F.27F.28F.28F.29F.29F.32F.32F.33F.33F.35F.35F.42F.42F.49F.49F.55F.55F.56F.56F.57F.57F.61F.61F.62F.62F.63F.63F.64F.64F.65F.65F.67F.67F.68F.68F.70F.70F.71F.71F.72F.72F.73F.73F.74F.74F.75F.75F.77F.77F.78F.78F.80F.80F.81F.81F.82F.82F.83F.83F.84F.84F.85F.85F.90F.90F.94F.94P.00P.01P.02P.04P.06P.14S.00S.01S.2S.02S.3S.03S.04S.05S.06S.07S.08S.09S.09S.10S.10S.11S.11S.13S.13S.14S.14S.15S.15S.16S.16S.17S.17S.19S.19S.20S.20S.21S.21S.22S.22S.23S.23S.24S.24S.25S.25S.26S.26S.27S.27S.28S.28S.29S.29S.30S.30S.31S.31S.32S.32S.33S.33S.34S.34S.37S.37S.39S.39S.40S.40S.41S.41S.42S.42S.46S.46S.53S.53S.54S.54S.55S.55S.56S.56S.57S.57S.58S.58S.59S.59S.76S.76S.86S.86S.88S.88S.92S.92S.93S.93S.96S.96S.97S.97S.98S.98S.99S.99

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