How to Replace a Sump Pump Float Switch

Authored by Tractor Supply Company

If your sump pump no longer switches on and off properly, you may need to replace the float switch. A broken float switch could be due to damage from debris or improper maintenance.

There are three options for anyone wanting to replace a float switch on a sump pump:

  • Replace the float switch.
  • Add a different float switch.
  • Let a plumber worry about it.

Disassembling and reassembling the float switch in a sump pump must be done correctly for the pump to continue working. For this reason, adding a different float switch may be easier than replacing the existing float switch if you are inexperienced.


Materials needed to replace a sump pump float switch:

  • Sump pump replacement switch
  • Screwdriver
  • Glue
  • Concrete sealant
  • Silicone sealant
  • Zip ties

Replacing a float switch

Follow these steps to replace the float switch on your sump pump:

Step 1: Prepare the sump pump

Allow the sump pump to run until all water has been removed from the sump basin. Once complete, disconnect the power to the sump pump.

Step 2: Remove the float switch

Read your owner's manual to determine where the float switch is located on your sump pump. Once you have removed the float switch from the pump unit, you are ready to open the float switch housing.

Step 3: Open the switch

Unscrew the connections on the float switch. You should now be able to see the electric switch inside. Remove the old switch and glue in the replacement using waterproof glue. Allow the glue to dry completely before reassembling the switch and replacing it into the pump.

Step 4: Replace the sump pump and test

Put the float switch back into the pump, making sure to thoroughly seal all areas that were previously sealed.

Adding a different float switch

If you are nervous about replacing the float switch, you can more easily add a new, external float switch equipped with a piggyback plug to bypass the existing float switch. This process may be easier for someone who is inexperienced but does not want to hire a plumber.

Follow these steps to add a new float switch to your sump pump:

Step 1: Prepare the sump pump

Allow the sump pump to run until all water has been removed from the sump basin. Once complete, disconnect the power to the sump pump.

Step 2: Bypass and seal the original switch

You will need to bypass the electrical wiring from the old switch and have it ready to connect to the new switch. Once you have bypassed the circuit, seal the electrical housing to the old switch with silicone sealant.

Step 3: Attach the switch to the pump housing

Use a zip tie to loosely attach the new switch to the pump housing. Attach the bypassed electrical wire to the new switch, and then plug the switch into the outlet. So the new switch should now be fully connected to the pump.

Step 4: Test the pump

Once everything is reassembled, fill the sump basin with water and adjust the replacement switch attachment point so that the pump turns on at an easy-to-test level. When you see that the pump is working properly, secure the switch in place onto the exterior of the pump housing with a zip tie