Video · Sump Pumps

How Does a Sump Pump Work? The Float Starts Everything

Water drains into a pit in your basement floor. As it rises, a float lifts and switches the pump on, the pump pushes the water up and out through a pipe, and a check valve keeps it from falling back.

Job footageSwiftPro

Topic
Sump Pumps
Length
0:29
Posted
September 30, 2026
Shot by
The SwiftPro crew, Northern Virginia

What you’re seeing in this video

It opens on an old, rusted sump basin lid, the cover over the pit where groundwater collects under a basement floor. A tech in a black long-sleeve shirt then carries lengths of white PVC pipe across a driveway past the lawn and a pickup.

Inside, the new discharge piping runs up from the pit with a check valve in the line. Text on screen explains the float switch, the part that decides when the pump runs.

Why it matters in your house

  • The check valve is the one people forget. Without it, the water in the pipe drops back into the pit every cycle, and the pump runs far more often to move the same water.
  • Know where your discharge pipe ends outside. If it dumps right next to the foundation, much of that water soaks back down and returns to the pit.
  • A rusted lid like that one usually means an old system. If you can't remember when the pump went in, test it before the next big storm.

What does a sump pump actually do?

It keeps groundwater from rising into your basement. Drain tile around the foundation sends water to a pit, and the pump empties that pit whenever the water gets high enough to lift the float. A healthy one runs a little during wet weather and sits quiet when it's dry. You only notice it when it stops.

Want it done at your place? See Sump Pumps at SwiftPro or call (703) 997-9757.

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