I came home a few days ago to find my sump pump running continuously. I have a battery backup pump which kicked in so fortunately no flooding.

I have a regular sump pump, connected as a piggy back onto an SJE VerticalMaster II. I figured the VerticalMaster was broken, so bought a new one at the weekend, changed it, and every thing worked fine.

Two days later, the same thing has happened again. So I've replaced the new float switch, with the old one, and it all works again. I'm sure in a few days, I'll be switching them over again!

It seems like the float switch is resetting itself after a while, and then gets stuck. I tested the one I took out, with a lamp, and it is on the whole time, as i move the float up and down.

Can anyone help me explain why this might be happening? We have had some cold weather the last few days, that's the only thing that has changed.