A sump pump motor is built to run in short bursts, not around the clock, and one that never cycles off will burn out in a matter of days or weeks. So when you notice the pump humming long after the last storm passed, time is already working against you. What helps is that a pump running nonstop almost always points to one of a handful of specific problems, and most of them are straightforward for a plumber to sort out once you know where to look.
Here in metro Atlanta, sump pumps tend to show up in homes with finished basements or crawl spaces that sit low on the lot, and our red clay soil holds water long after the rain stops. That combination is exactly why a pump here can keep running for hours when the storm is already gone.
The Check Valve Is the Usual Suspect
The check valve is a one-way flap on the discharge line that stops water from sliding back down into the pit once the pump pushes it up and out. When that valve wears out or sticks open, every gallon the pump sends up the pipe drains right back into the basin. The pump empties the pit, the water returns, the float rises again, and the whole cycle restarts within seconds. You get a pump that runs and runs while the water level barely moves.
This is one of the most common reasons a sump pump keeps running, and a failed check valve is an inexpensive part. The trick is confirming that the valve is the actual problem and not just a symptom of something further down the line.
A Stuck Float Switch
The float switch is what tells the pump when to turn on and off. It rides up with the water and trips the motor, then drops back down and shuts it off. When the float gets hung up on the side of the pit, tangled in the discharge pipe, or clogged with debris, it stays in the on position and the motor keeps running even though there is nothing left to pump. In a tight or older basin, floats catch on the wall more often than you would think.
If you can safely reach the pit, look at whether the float has room to move freely. A float pinned against the wall is a quick thing to spot. What you should not do is keep running a pump that is cycling on a dry pit, because running with no water to move is how the motor overheats and dies.
The Pump May Simply Be Too Small
Sometimes nothing is broken at all. If the pump was undersized for the property when it was installed, a heavy Georgia downpour delivers more water than the unit can clear, so it runs flat out just to keep pace. It never gets ahead of the water, so it never shuts off. This shows up most during the wet stretches of spring, and it tells you the home needs a pump matched to the actual water load rather than the smallest unit that fit the pit.
Water That Should Not Be There
A pump that runs long after the weather clears is often reacting to water that should not be filling the pit. A high water table, poor yard grading that funnels runoff toward the foundation, or a hidden plumbing leak feeding groundwater into the basin will all keep the float rising. Finding the source is the part that separates a real fix from a pump you just keep replacing every couple of years.
Reading the Signs
The pattern of how your pump misbehaves usually points straight at the cause, below is what each tends to mean:
What is happening |
The likely cause |
The fix |
Pump runs but the pit never empties |
A stuck check valve is letting water fall back into the pit after each cycle |
Replace the check valve |
Motor hums or runs with no water moving |
The float switch is jammed against the pit wall in the on position |
Reposition or replace the float |
Runs constantly during heavy rain, keeps up but never rests |
The pump is undersized for the water volume the lot produces |
Upsize the pump |
Runs long after the rain has stopped |
Groundwater or a plumbing leak is feeding the pit continuously |
Locate the water source |
What You Can Check Before You Call
A couple of things are safe to look at yourself. Lift the lid and check whether the float can swing freely, since a snagged float is easy to see. Listen for whether water is actually moving through the discharge line or whether the motor is just running dry. If you hear the pump cycle on, push water up, and then hear it rush right back down into the pit, your check valve is the likely culprit.
Past those two checks, the work moves into replacing valves, testing float switches, and figuring out where unexpected water is coming from, and that is the point where a licensed plumber helps. RooterPLUS! has handled sump pump service across metro Atlanta for three decades, and we would rather fix the real cause once than have you buy a new pump every spring.
Sump Pump That Will Not Shut Off?
RooterPLUS! has kept metro Atlanta basements and crawl spaces dry since 1994, across more than 100,000 homes. We will find why your pump keeps running, fix the real cause, and give you a written estimate before any work starts.
Live dispatch answers 24/7 with no upcharge for nights, weekends, or holidays. GA Plumbing License #MP207808.
Call 770-888-1931 or schedule service online.
