Low
S.36 on Vaillant ecoTEC exclusive 627 VU 256/5-7

Your temperature settings are too low for the boiler to start heating, so the system is currently on standby.

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

Target value for ext. controller lower than 20 °C / 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 Vaillantpro 0020193966 04 Ecotec Exclusive System Installation I 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

Check your wall thermostat or room controllerIncrease the temperature setting to above 20°CEnsure the thermostat is turned on and has working batteries

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Related fault codes

S.31View →S.34View →

All 72 fault codes on the ecoTEC exclusive 627 VU 256/5-7

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.33F.35F.42F.49F.55F.56F.57F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.80F.81F.82F.83F.84F.85F.90F.94S.34S.37S.39S.40S.41S.42S.46S.53S.54S.55S.56S.57S.58S.59S.76S.86S.88S.92S.93S.96S.97S.98S.99

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