Informational Guide

Sump Pump Keeps Running (Common Reasons & How To Fix)

by Andrew

A sump pump is designed to remove excess water from your home and stop flooding in your basement or crawl space. Your sump pump is triggered when the water level in the sump basin gets to a certain point and run until the water is drained.  

In some cases, the sump pump keeps running, which can cause issues. In this guide, we'll help explain why this is happening and what you can do to resolve the problem. 

Every sump pump can experience issues, and even reliable brands like Zoeller can have issues. It’s important that you take action as quickly as possible, but first, you need to diagnose and understand the problem. We've given a breakdown of the most common reasons Zoeller, or other brand sump pumps, keep running and how you can resolve the issue.  

1. Bad/Jammed Float Switch 

Your sump pump comes with a float switch inside the unit. These are designed with lightweight materials and are often filled with air so that they'll float on top of the water as it rises in the basin. Once the float switch reaches a certain level, it will indicate that there's too much water in the basin and trigger the pump to start operating. As the water drops, the float switch should go down and signal the pump to turn off again.  

If your float switch becomes jammed in the on position, then your sump pump will continue running constantly. This usually happens when the float switch has become jammed due to a loose wire or some other debris. The sump pump won’t turn off until you fix the issue.  

How To Fix 

A jammed or faulty float switch is a fairly common problem, but it's fairly easy to fix. Start by disconnecting the power and removing the sump basin lid. Check for any visible debris or if the float is blocked. Test it by pouring water into the basin and seeing if the float goes up without interference. If it doesn’t, you’ll need to get a new float, but you can purchase these very cheaply. Once you’re done, put the lid back on, switch on the power and check to see if the sump pump is working properly again.  

2. Faulty Check Valve 

Sump pumps work by pumping the excess water out of your home, but because they are located in the lowest part of your house, they often have to pump it up 8 feet or more. As water rises through your pipes, there's a risk that as the pump switches off, the water will just flow straight back down into the basin and trigger the pump to start again. A check valve is installed to stop the water from flowing straight back down again. If there's an issue with the check valve, then your sump pump can get into a cycle of continuously turning on every few seconds.  


How To Fix 

The good news is that a check valve issue is relatively easy to resolve, but the bad news is that most check valves can only be replaced, not repaired. Make sure the device is completely turned off, and start by following the discharge line out of the sump pump system until you reach the check valve. Look for any visible signs of damage to confirm this is the issue, and then use a plumber’s wrench to loosen and remove it. You can purchase a replacement check valve at your local hardware store, but it's often worth bringing in the faulty one to make sure you get an exact replacement. Fit the new valve in the same place as the old one and turn everything back on. Your sump pump should be working properly now.  

3. Faulty Impeller 

Your impeller is the internal component that turns and generates the momentum to pump the water out of the basin. Unfortunately, the impeller can easily become blocked by stones and other debris, which means that your pump is running, but the water isn't being pumped. This leads to your sump pump running continuously because the water level isn't dropping as it should.  

How To Fix 

The most common reason your impeller fails is due to a blockage. Start by turning off your pump and then open up the basin lid to examine the pump. You should be able to see the impeller and hopefully remove any small stones or debris that might be blocking it. Look for any other signs of damage that might indicate that the impeller is broken. Hopefully, you're able to unblock the pump, and it will start working normally again. If it isn't working still, or a blockage isn't the problem, you'll probably have to replace the whole pump as it isn’t normally possible to replace the individual components. 

4. Underground Leak 

Another common issue for your sump pump running is an underground leak that you aren't aware of. This often happens if there's a leak in your sewage line or an issue with the sprinkler pipe, so excess water is draining into your pump. When this happens, it means that your pump is working overtime to get rid of water that's constantly running into the pump system.  

How To Fix 

The good news here is that your sump pump is probably running correctly; it's just working continuously to do the job. The bad news is that these underground leaks can be serious and lead to structural damage to your foundations. You need to get this sorted quickly, and to do that, you'll have to get a professional to assess the damage. Once the leak is fixed, your sump pump should start running normally again.  

5. High Water Table 

The water table is the water running underground beneath your home. When there's heavy rain, the water table will rise so it's nearer the surface, and then can mean the lowest part of your home becomes flooded with water. If your house is directly on top of a high-water table line, then you're always going to be at risk of flooding, and even a small amount of rain can cause an issue. Ultimately, your home has been built in the wrong place, and your sump pump is running continuously to manage the problem.  

How To Fix 

As more homes are built, it's becoming increasingly common for homes to be built on potential flood plains, and unsuspecting homeowners are being caught out. Unfortunately, there's no easy fix to this, but you can look to build a deep well outside your home as this will capture some of the extra water and prevent it from coming into your home. The other option is simply to buy a sump pump which is specially made for continuous running, so you're constantly fighting against the high water table. Neither option is perfect, but they should keep your basement dry.  

6. Undersized Sump Pump 

Every sump pump has different specifications with different motors. They’re designed to run in a specific size of area, but if your sump pump is too small for your basement or crawl space, it will need to run for longer to get the job done. This can lead to your sump pump continuously starting and stopping until the machine gets run down and may mean that the water isn't being adequately drained from your home. 

How To Fix 

Most sump pumps have a 1/3 horsepower motor which is enough for the majority of homes. However, if you find the area is staying damp even though the pump is constantly running, then you need to invest in a larger pump. Make sure you check the specifications closely before buying a new sump pump to avoid this issue. Once the larger pump is installed, it should solve the problem.  

Why Is It Bad For Your Sump Pump To Run Continuously?

Your sump pump is designed to pump out water, so if it's running when there's no water, it's an issue.

Some sump pumps will start to short-cycle every 30 seconds, which is definitely not normal. If your sump pump is running continuously, it can cause the motor to overheat. This can cause internal damage, and eventually the motor will burn out.

The end result is that your sump pump won't be able to get rid of water from your home, and you'll probably have to pay for a new one. 

Sump Pump Keeps Running But Not Pumping 

It’s one thing if your sump pump is continuously running when it isn’t needed, but it’s the worst-case scenario if your sump pump is running but not pumping water.

This will mean that your pump is overheating and causing itself damage, and your home will still have groundwater gathering in the basement.  

If this happens, it's usually because your check valve is broken, the discharge pipe is clogged, the impeller isn't spinning, or your drain line is too small.  

If your check valve is broken, then you’ll need to buy a new one and replace it. You should be able to do this yourself using a wrench, but make sure the pump is turned off before you start work.  

Your discharge pipe can become clogged by dirt and debris over time. This prevents water from flowing out of your pump system and essentially makes your sump pump useless. You’ll need to turn off the pump, disconnect it, and clean out the pipes. Directing a pressure hose through them often does the trick, but you can also find special cleaners.  

If the impeller isn't spinning, then no water is going to be pumped out of your system no matter how hard it works. This is usually caused by a blockage, and you should be able to manually remove the debris from your sump pump and get it moving again.  

If your drain lines are too small, it means that water isn't pumping out of your system quickly enough, and water is filling up faster than it goes out. Check the manual for your pump and see if it gives any recommendations on the pipe diameter. You’ll need to do some work replacing the pipes or hire a professional to do it for you 

Sump Pump Keeps Running In Winter (DIY Fix Guide) 

In the colder months, your sump pump discharge line can become frozen and clogged with ice.

When ice blocks the pipes, water won't be able to pass through, and your sump pump will run continuously without having any effect.  

You can usually unfreeze the line using a hairdryer or space heater, but you may need to disconnect the pipe and pour some boiling water through it to remove the blockage.

For a long-term fix, you should make sure your discharge pipe is installed on a slope to avoid any water staying in the pipe long enough to freeze.  

frozen pump


Why does my sump pump run every 5 minutes? 

This could be because there is a lot of moisture around your home, and your sump pump is working hard to manage it, or it could be because there's an issue with the machine. Have a look at your check valve and floating arm to see if there’s an obvious issue that’s causing your pump to run too much.  

Why does my sump pump run when it's not raining? 

The water table could be high, and there could be an excess of groundwater coming into your home that your sump pump is dealing with. It could also indicate that there's a problem with your pump, so you may want to check your machine and make sure there are no obvious issues.  

How long can a sump pump run continuously? 

Most sump pumps can run for 6 to 24 hours continuously in order to deal with the wettest periods of the year. Some sump pumps are designed to run for longer, so if you live in a very wet area, you may benefit from this functionality.   

How often should a sump pump go off? 

Your sump pump will only go off when the water reaches a set height in your sump basin. How often it goes off depends on your location and climate, but it’s fairly common for it to go off 2-3 times a day.  


Your sump pump offers your home protection against flooding and excess groundwater, but if it starts to run continuously, it can damage the machinery. In some cases, the pump can keep starting and stopping without actually removing any water, damaging the machine without even keeping your home dry.  

Thankfully it's usually simple to diagnose and fix the issue, and hopefully you now have all the information to get your sump pump working correctly again.