My Fabia 1.4 BXE doesn't have classic temperature gauge on the dash. I started engine let it idle and checked coolant temperature on VCDS, after a while it was 104 degree Celsius.

Fan wasn't working. I enabled A/C, fan started work, so fan is fine. I let the engine cool down and I switched it off.

Why fan wasn't working when temperature was 104? Should I wait longer? 

For the fan to be triggered by the radiator thermoswitch, the temperature of the coolant at the thermoswitch location needs to exceed the threshold temperature.

Normally the position of the thermoswitch means it is measuring the coolant temperature after it has flowed all the way through the radiator, so you really want to know what the temperature is locally, where the thermoswitch is mounted.

I think the thermoswitch threshold temperature for low speed fan action is about 95°C. I would not be at all surprised if the coolant had lost more than 9°C of temperature between the engine head where your VCDS temperature is being measured, and the radiator outlet.

 

So yes, leave it for longer. Or get the engine working harder. 

 

Thanks. I will do that someday and leave feedback.