Runs for a second

Hi,
This is a relatively new dehumidifier.
When I open it all up, it looks brand new inside!
No frost, no mildew, all shiny and clean. :)
The problem is that I put the bucket in carefully trying to position it correctly.....I hear a little click....it runs for a second, and then stops.

I looked at the red button inside that would make contact with the back of the bucket.....and when I press it (as the bucket would) it MIGHT start....the most I would hear would be a click. If it did start, it would quickly stop.
I see what that red button is attched to inside the unit................what is that?
And how would I replace it?
And where would I get that part?
I read all the other messages....I hope I am not asking the same question.
Thank you.
MizzR