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Why Is My Sump Pump Running Constantly After a Storm?

July 08, 2024

After a heavy rainstorm, it’s common to hear your sump pump running often for a few days. But if your sump pump seems to be running continuously, it could be a sign there’s something wrong with it.

There are a few hazards to sump pumps running continuously. One is that the sump pump components will wear out faster, requiring more frequent repairs or even a premature replacement. Since a sump pump runs on electricity, having it run continuously costs you extra money on your energy bill. Additionally, sump pumps can overheat, particularly if they’re running in an empty sump pit (a water collection hole).

If your sump pump won’t turn off, first check to see if there is water in the sump pit. Is there water in the pit? If not, the float switch is probably “caught.” If yes, the issue could be:

  • A clogged inlet screen
  • A leaking discharge line
  • A malfunctioning check valve
  • A broken impeller
  • An improperly sized sump pump

Most sump pump problems require a professional’s assistance, but it can be helpful to troubleshoot the problem from home first. Check these key components when your sump pump won’t turn off before calling a plumber for support.

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Flooding can cause serious issues in your home. That’s why we promise to install or repair your sump pump right—the first time. When you schedule service with Ranshaw Plumbing & Heating, you know you’re getting dependable service from experienced professionals. To schedule your sump pump repair, give us a call at (718) 767-0707.

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Caught Float Switch


The float switch stuck in the “on” position is the simplest reason your sump pump is continuously running, especially if your sump pump keeps running even though your sump pit is empty.

Typically, sump pumps only turn on when the water level in the sump pit reaches a certain height. To measure this height, sump pumps are equipped with a buoyant ball—the float switch—attached to an activator arm. The float switch rests on the surface of the water in the sump pit, and once the water level rises to a certain height, the switch turns the sump pump on.

Unfortunately, it’s very easy for the float switch to become caught or wedged in the sump pit, where it can get stuck in the “on” position.

  • If your sump pit is dirty, the float switch can catch debris stuck to the pit walls as the water level decreases.
  • Pedestal pumps can vibrate when turned on, which can cause the float switch to drift and become wedged against the side of the sump pit.

The solution: Disconnect your sump pump from power, then readjust the float switch to be resting naturally in the pit. Reconnect the power and add some water to the pit to ensure the sump pump turns on and off normally.

Clogged Inlet Screen

All water pushed by your sump pump passes through the inlet screen first. If your inlet screen is clogged with debris, water will struggle to pass through it, making your sump pump run continuously.

The inlet screen works the same way as a filter. Water passes through it and deposits dirt and other debris before they get to your sump pump. The more clogged the inlet screen becomes, the harder it is for water to pass through it. Since water is slowly streaming into the sump pit, your sump pump slowly pumps it out, causing it to run constantly.

The solution:

  1. Unplug your sump pump and pull it from the sump pit
  2. Clear the inlet screen of dirt and debris using a small tool, like a toothbrush
  3. Replace it in the pit and turn it back on to see whether it can empty the sump pit.

Leaking Discharge Line

Sump pumps push water out of the sump pit up a vertical pipe called a discharge line. If the discharge line has cracks or leaks, it could cause your sump pump to run continuously.

All water passes through the discharge line on its way out of your home, but leaks in the line mean some water will escape the pipe and fall back into the sump pit. Your sump pump will push this water back up the discharge line, only for it to leak back into the pit again. This cycle will cause your sump pump to keep running as it tries to push the same water out of the pit repeatedly.

The solution: Visually inspect your discharge line for cracks or leaks. If you see any, call a plumber for a repair.

Malfunctioning Check Valve


The check valve is a valve located on the discharge line that prevents a backflow of water when your sump pump turns off. If your check valve isn’t working properly, your sump pump will keep refilling with water from the discharge pipe when it turns off and will turn back on to try and remove it.

Like leaks in your discharge line, a malfunctioning check valve makes it impossible for your sump pump to empty the sump pit fully. If you notice your sump pump is turning on and off continuously, the check valve might be broken.

The solution: Unplug your sump pump, then inspect the check valve. Try to open and close it manually. If it gets stuck or won’t move, you may need to call a plumber to replace it.

Broken Impeller

Every sump pump pulls in water and pushes it out with an impeller fan. If your impeller isn’t working properly, your pump will sound like it’s turned on, but it won’t push any water out of your sump pit.

When the water level in your sump pit rises or stays the same even though your sump pump is running, you might have a broken impeller. Without the part working, the sump pump can’t push any water out of the sump pit and up the discharge line.

The solution: Impellers should be replaced by an experienced plumber.

Improperly Sized Sump Pump

An improperly sized sump pump won’t be able to keep up with the volume of water filling the sump pit, which will cause it to run continuously.

Every sump pump has a maximum pumping capacity measured in gallons per hour. When a plumber installed your sump pump, they should have sized it to fit the amount of water expected to enter the sump pit during wet conditions.

Undersized sump pumps can’t push out as much water as is coming in, leading them to run constantly to try and empty the sump pit. One way to tell if your sump pump is undersized is to run it and see if the water level rises and falls in the pit. If it doesn’t, it’s undersized.

The solution: Sump pumps should always be sized by a professional. If you believe your sump pump is undersized, call a plumber for an evaluation.

Ranshaw Plumbing & Heating Will Defend Your Home Against Flood Damage

When you’re worried about water damage, you want peace of mind that your home is protected. At Ranshaw Plumbing & Heating, we have over 60 years of experience serving the Queens community. As a licensed plumbing company, we’re reliable, dependable professionals you can trust to do the job right the first time.

Our plumbers can repair almost every sump pump model in just one visit, saving you time and money. When you’re in need of sump pump support, call Ranshaw Plumbing & Heating at (718) 767-0707 to schedule an appointment or click the button below to schedule online.

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