Sump pumps can be a lifesaver as they work to help ensure that your basement or crawl space doesn’t flood. Without a working sump pump, heavy rains or snow melt can lead to water seeping up from underneath your foundation. If left unchecked, all of that water could quickly lead to issues with mold or potentially damage your foundation or cause part of the home to start to sink.

However, it simply isn’t enough to have a sump pump installed as you also need to periodically check to make sure the unit is still working properly and pumping efficiently. As with any other type of equipment, sump pumps can have issues that will prevent them from running or cause them not to pump as they should, and the unit can also simply fail due to age. If your sump pump were ever to fail, it could lead to major flooding issues before you even realize the unit isn’t working. This is why we always recommend testing your sump pump every two to three months and especially before any major storms, and here is a quick overview of the ways you can test your sump pump and also what steps to take if the unit doesn’t work as it should.

Testing a Sump Pump With Water

The best way to test a sump is to fill the sump basin with water until the unit starts running and then make sure it is pumping water out of the basin as it should. It is possible to test some units to make sure that they still run without filling the basin with water, but this is only recommended as a last resort if for some reason you can’t fill the basin. The reason is that running the unit without water can quickly cause the motor to overheat if you let it run dry for more than a few seconds.

The easiest way to test your sump pump is to run a garden hose from outside to the basin. If this isn’t possible or you’re testing the sump pump during winter when your hose bibs are shut off, you will then need to use your shower or other plumbing fixture to fill up two 5-gallon bucks with water and then dump them into the sump basin.

You will usually need to put around 7 gallons of water in the basin in order to trigger the float switch so the unit turns on, but this can differ depending on the type of switch the pump has and the size of the sump basin. Once you’ve added enough water, the unit should automatically turn on and quickly pump all the water out. If everything works properly the first time, we would then recommend putting 10 to 15 gallons of water in the basin again so that you can then make sure the unit is pumping efficiently.

Most sump pumps have a pumping capacity of somewhere between 40 and 55 gallons of water per minute. If you add 15 gallons of water to the basin, the pump should be able to mostly empty the basin in 20 seconds or so. If the unit takes much longer than this, it indicates that the unit is pumping as effectively as it should so you will then need to move on to troubleshooting the problem.

Dry Testing a Sump Pump

Depending on the specific model of sump pump you have, you may be able to test to at least make sure it turns on without filling up the basin. However, this is only possible on units that use some type of float switch. If your unit does have a float switch, all you need to do is reach down into the basin and lift up the float 6 to 8 inches. Lifting the float will trigger the internal mechanism and switch the pump on. If the pump switches on, you should then immediately set the float back down so that the unit turns off to prevent possible damage to the motor caused by overheating.

More advanced units often use either a diaphragm switch or an electronic switch instead of the traditional float switch, and these types of switches will only work when there is water in the basin. A diaphragm switch works by sensing pressure changes. When the basin starts to fill, the water puts pressure on the switch and triggers the pump to run. The pump will then continue to run until the basin is mostly empty and the pressure returns to normal.

Electronic switches are even more advanced. This type of switch has an electrode that constantly sends out a small electrical current that can sense the presence of water in the sump basin. If water is present, the pump will turn on and run until the switch again senses that no more water is present.

Troubleshooting Common Sump Pump Problems

If your sump pump won’t turn on at all, you should first check to make sure that the unit is plugged in. It is also a good idea to test that the outlet is working by plugging another device into it. If the outlet isn’t working, you should then check your main electrical panel to make sure there isn’t a tripped circuit breaker.

If the problem is related to the electrical outlet, you will need to have it checked by an electrician to see why it isn’t working. If the outlet is fine and your sump pump won’t turn on, you can be fairly certain that the unit is bad. If your sump pump is fairly new, you may be able to have it repaired. However, if your pump is more than five years old, it would be reasonable to consider having a new unit installed.

If your sump pump turns on but won’t pump or pumps much more slowly than it should, it usually indicates that there is either a problem with the impeller or that the intake screen on the bottom of the pump is clogged with dirt and debris. In this situation, you will want to take the pump out of the basin and use a toothbrush to thoroughly clean the intake screen. If you have a submersible sump pump, the screen will be located underneath the base of the unit. On pedestal sump pumps, the screen will be at the end of the arm or tube that sticks down into the basin.

After cleaning the screen, you can then put the pump back into the basin and test it again. If it still doesn’t work, you will then need to have it inspected and either repaired or replaced depending on the age of the pump and the specific cause of the issue.

The fact that the intake screen can get clogged quite easily means it is always a good idea to remove the pump and clean the screen at least once or twice a year. If your sump pump runs quite frequently, you may want to clean the screen every few months whenever you test the pump.

If you’re having any issues with your sump pump or need a new unit installed, you can count on the experienced team at John Henry's Plumbing, Heating, Air, and Electrical. We offer a full range of plumbing and drain services, and we have also been helping customers throughout the Lincoln area with their home’s heating and cooling needs for nearly 20 years. Give us a call today if you have any questions or need to schedule a service call.

company icon