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Why Does My Sump Pump Keep Turning On And Off? Here is What You Need to Know

A sump pump protects the space from water damage in any basement, underground den, or pit. But over time, it can start acting up the way you don’t want it to. If it cycles too frequently, chances are that the motor will wear out. Thus, it may start malfunctioning.

So, why does my sump pump keep turning on and off? This could happen for a few different reasons. It could be a sign of a defective float switch, check valve, impeller, or the sump pit itself.

Another possible reason is that your pump can’t keep up with the amount of water that’s coming in. There are a few things you can do about this situation. And we are here to see that you get your sump pump up and running in no time.

Table: Sump Pump Keep Turning On And Off (Problems And Solutions)

Here is a table of causes and possible solutions for you.

Defective Float SwitchReplace the float switch with a new one. Make sure it is compatible with your sump pump model
Check for proper movement and ensure it is not clogged
Damaged Check ValveInstall or replace a check valve to prevent water from flowing back into the sump pit. Check for proper installation and functionality
Blocked Discharge PipeClear the clog in the discharge pipe using a wire hanger or drain snake. Avoid using liquid drain cleaners in the sump pump
Undersized Sump PumpInstall a proper sump pump that can handle the water volume effectively
Clogged Inlet ScreenClean the inlet screen by removing debris
Broken ImpellerRepair it yourself or call for services
Faulty Pressure SwitchAdjust the pressure switch as needed
Check with a professional
Continuous Inflow of WaterLook for any plumbing leaks and use tape to seal them
Power Supply ProblemsCheck the circuit breaker, power cord, and connections for any issues. Ensure the sump pump is receiving consistent and adequate power

Why Does My Sump Pump Keep Turning On And Off?

Now, we will dive into more details for your better understanding:

1. Damaged Float Switch

The float switch is perhaps the most important part of the sump pump. A damaged float switch may become stuck in either the “on” or “off” position. It will result in continuous running or failure to activate the pump when needed. This can lead to excessive operation of the pump.

A defective pump will:

  • Overheat the motor, causing premature wear
  • Have a hard time detecting the precise water level in the pit
  • Damage to the mechanism of the float switch


The only solution we will give you here is to replace the damaged one with a new and compatible one. Also, regularly check up on your float switch after replacement.

2. Defective Check Valve

Check valve stops water from flowing in reverse. It ensures that water discharged from the pump does not flow back into the sump pit. But when the check valve gets damaged, a few things can happen:

  • A damaged check valve may fail to seal properly. Which may allow water to flow back into the sump pit through the discharge pipe. This backflow can lead to the continuous cycling of water.
  • With a damaged check valve, the sump pump has to work harder to overcome the backflow of water. This puts additional strain on the pump.


Here you can do two things: 

  • You can identify the leaks in the check valve. If the leaks are not big, you can put a tape in it.
  • If the check valve is repairable, change it. Turn off the pump, disconnect the pump, and get a replacement. You can find it above the sump pump.

3. Blocked Discharge Pipe

Upon inspection, if you can’t find any problem with the check valve or the float switch, the problem may lie with the discharge pipe. Sometimes dirt and debris may enter the pipe. And over time they build up and hamper its work process.

A blocked discharge pipe will:

  • Create blockage that hinders water from exiting the pump effectively.


Clear the clog using a wire hanger or a drain snake. Carefully insert the wire hanger or drain snake into the discharge pipe and gently maneuver it. Do not put liquid drain cleaner into the pipe.

4. Clogged Inlet Screen

Certain sump pump models incorporate an inlet screen. It serves as somewhat of a barrier. Simply put, it allows water to pass through while preventing debris from entering the motor.

While this design feature is a convenient one, there are instances when the inlet screen itself becomes obstructed. This can cause:

  • Disruption in the normal flow of water into and out of the system. This in turn impedes the pump’s efficiency


  1. Carefully remove the inlet screen and clean it thoroughly.
  2. Use a soft brush, such as a toothbrush for this.
  3. Gently scrub away any debris or sediment that has accumulated on the screen.
  4. Rinse it with water to ensure all particles are removed.

5. Undersized Sump Pump

An undersized sump pump poses a few problems:

  • It lacks the capacity to remove water from the system as quickly as it enters. This puts pressure on the pump.
  • An undersized sump pump runs for extended periods, to pump excess water. It can cause the pump to break down.


If you notice this issue, replace it with a properly sized pump.

6. Broken Impeller

The impeller is a motorized fan within the sump pump. It is responsible for drawing water into the pump and propelling it upward through the discharge pipe. If the impeller breaks, the sump pump will continuously run without effectively moving water in or out of the system.

A broken impeller leads to several issues:

  • The damaged impeller fails to create the necessary suction and pressure to efficiently move water. This results in reduced water intake and discharge capabilities.
  • With a broken impeller, the sump pump will run continuously in an attempt to function properly. But no matter how much it rotates, it will be unable to effectively pump out water. 


We will advise you here to contact a qualified HVAC technician or sump pump specialist

7. Power Supply Issue

Sometimes, issues like electrical surges or wiring problems can disrupt the pump’s operation. An electrical problem may lead to:

  • Abrupt on and off the power outlet of the sump pump.


Check your circuit breaker, power cord, electrical connection, and dedicated circuit. If you find any problem there, you can solve the problem with electrical tools. Or you can call your verified electrician.

8. Defective Pressure Switch

Certain sump pumps utilize a pressure switch to regulate their operation. This switch detects the water pressure within the sump pit and triggers the pump to turn on or off accordingly. If there is any fault in the switch, it will,

  • Either make the pump run continuously
  • Or, make it turn on and off frequently


You need to check and adjust the switch. A professional can help you in this matter.

9. Constant Water Flow

And lastly, we have the most benign problem here. If you live in a place where it rains a lot or if it is the season of heavy rain chances are more water will accumulate in the pump pit. This constant water inflow will make the sump pump turn on and off.

Sometimes it could be another reason too. Especially if there is no rain.


Look for this mysterious source of water. Fix any drainage leaks or get another drainage solution.


We are sure your curious mind has other questions about the sump pump. All your other questions are addressed here:

Q. How long should a sump pump run per cycle?

The duration of a sump pump’s run time per cycle can vary depending on several factors.  For instance, the water level, pump capacity, and the amount of water entering the sump pit.

On average, a sump pump may run for a few seconds to a couple of minutes per cycle. However, during heavy rain or periods of high water intrusion, the pump may run for longer.

Q. How to fix the short cycling sump pump?

The short cycling problem is usually related to a defective float switch. Inspect the switch and if necessary, replace it. Other factors might also play here. So, check for other possible causes as well.

Q. Is it normal for a sump pump to run every 3-5 minutes?

No, it is not. It suggests that there may be an issue with excessive water infiltration into the sump pit or a malfunctioning pump.

Last Words

So, why does my sump pump keep turning on and off? The fact here is that it is due to one reason or to a combination of two or more. Thus, when you are trying to fix your sump pump look for everything that can cause this issue.

Moreover, you need to invest your time in regular maintenance and check-ups. Moreover, if you’re left confused, do not hesitate to call a professional. With that being said, we hope you found what you’re looking for, and good luck!