Well, you will surprised to hear that that isn't always the case.

There are many reasons as to why your extract fan isn't working correctly and most of the time its down to either a poorly installed ducting system or the fan is a waste of money that's not suitable for any type of bathroom extraction.

In the video I will be showing you exactly that, a fan that is spinning away and its not doing anything at all.

The only way to tell in fact is to test the fan with the right test equipment to ensure the fan performs.