This weekend, possibly beyond my scope of ability, I tried to replace
the pressure switch on my sewage pump (Hydromatic skv40). I got a new
Hydromatic pressure switch from a local plumber's parts dept - looks
just like the one I'm replacing.
I thought all I would have to do is remove the old pressure switch and
attach the new one. After getting it attached and piggy backing the
pump cord/plug, I filled the basin with water, but the pressure switch
never kicks on. I can reach in and push the bottom of the switch and
the pump kicks on, but it isn't firing by itself.

This was the same problem with the one I am replacing. The pump works
fine when I plug it directly into the wall so I assumed it was the
pressure switch? How does the pressure switch work? Does the basin
have to be air tight to create enough pressure?

-Thanks -