Automatic Bilge Pump Won't Shut Off

[zoom555]

Last year I installed a small bilge pump with a built-in float switch. I also installed an auto/manual/off switch and generally left the pump in auto mode.

After a long spring that involved a rudder rebuild and assorted related problems, I launched last week. I've discovered that the bilge pump no longer reliably shuts itself off. If left on auto, it will run until it's quite hot.

The pump is a Seasense Auto 800 GPH model (manufacturers' info here).

Any suggestions on how I might diagnose the problem?

[Hobos]

Sticky float or sticky contacts.

[bubb2]

It's gunked up. Pull it apart and clean it.

[scottyt]

i had several float switches fail, either wont shut off or wont run. i went the ultima electronic switch and its been fine. i just check it monthly and wipe it off, as most time i read about it not working was due to it being dirty

[RogerDuncan]

I agree - clean it out . bilges can get cruddy

[OceanHound]

I had the same problem twice with my Auto 500 GPH Bilge Pump
When the Auto Switch stops working, I just pull it apart and clean up the contacts. Usually lasts another 6 months before I need to clean it up again