Basements and crawl spaces are often susceptible to flooding as groundwater can easily seep inside after heavy rains. A leak in your main water or sewer line or your sprinkler system can also quickly lead to flooding. Sump pumps work to lessen the risk of water damage and mold growth by capturing this water and pumping it back outside, and today we’re going to give you a full overview of exactly how they work to prevent your basement from flooding.

Understanding the Different Parts of a Sump Pump

Sump pumps have a number of different parts that work together so that the unit can draw water out of the basement or crawl space and pump it outside and away from the home. A sump pump is installed in or on top of a large plastic container known as a sump basin or sump pit. The sump pit is installed so that the top of it is right at the ground level and the bottom extends around 24 to 36 inches down into the ground.

The sump pump itself is either hardwired into the home’s electrical system or simply plugged into a nearby outlet to ensure that the unit has the electricity needed to power its small motor. Many sump pumps also come with a backup battery. While not essential, a backup battery is definitely a great feature as it will ensure that the sump pump can continue to run even if the power is out.

A float or other type of switch works to sense how much water is in the sump pit and will automatically trigger the unit to turn on once the water reaches a certain level. This triggers the motor to run and start spinning the unit’s impeller blades, which creates suction so that the water can be drawn up and out of the pit. Once out of the pit, the water then flows through a series of pipes that then lead out of the home.

Depending on how the system was set up, the outlet pipe may either empty out into the lawn or run toward a storm drain. Even though it is against building codes, you will also occasionally see sump pumps that are connected directly to the home’s sewage system.

How a Sump Pump Float Switch Works

Whenever lots of water is present, it naturally flows from the surrounding ground into the sump pit. Most sump pumps use some type of float switch that basically measures the water level and triggers the pump to turn on and off.

The most common type is a tethered float switch, which is a hollow floating element that has a steel ball inside it. When the water rises and the switch begins to float, the steel ball inside the float shifts and activates an electronic switch. This closes the electrical circuit so that electricity starts to flow and the sump begins to run. Once the water level recedes past a certain point, the steel ball again moves so that the switch deactivates opening the circuit and shutting off power to the pump.

There are also sump pumps that instead use a vertical float switch that is connected to a rod and lever arm and works somewhat similarly to a toilet float. When this type of switch starts to float, it pushes against the rod, which raises the lever arm and activates the switch so that the pump starts running. This type of float switch is generally more reliable than a tethered float switch and is best suited for use in smaller sump pits.

You can also find sump pumps that don’t use a float and instead use either a diaphragm switch or an electronic switch, and these are by far the most reliable. A diaphragm switch works by sensing pressure. When the sump pit starts to fill, the water eventually puts enough pressure on the switch that it then activates to turn on the pump.

Electronic switches are even more advanced and use electrical probes to sense the presence of water in the sump pit. The unit constantly sends a small electrical current through the probes. An internal sensor in the switch constantly measures the electrical resistance in the probes. When water is present in the sump pit, the electrical resistance changes. Once the resistance passes a set level, the switch then activates to turn the pump on. The sensor then continues measuring the resistance and will shut the pump off whenever it is back to normal.

Submersible vs. Pedestal Sump Pumps

Sump pumps can be either submersible or pedestal-style units. A submersible sump pump sits at the bottom of the sump pit, whereas pedestal pumps sit on top of the sump pit and have a long pole that sticks down into the pit. Both types of units use an impeller to create suction and draw out the water from the pit.

With a submersible pump, the motor and impeller are located within the body of the pump itself. A pedestal sump pump has its motor at the top of the basin, while the impeller is located at the end of the pole inside the basin.

Submersible pumps are typically a bit more powerful as they tend to have slightly larger motors than pedestal units. This makes them much better suited for places that are more prone to flooding or when the water needs to be pumped much further vertically or horizontally.

Pedestal pumps, on the other hand, tend to be a bit cheaper and easier to maintain since they don’t sit inside the pit. They can also sometimes last longer since there is no chance that water can get inside the unit’s motor, which could happen if the waterproof coating on a submersible unit gets damaged. However, pedestal pumps are also much louder than submersible units. This is because the water that surrounds a submersible pump works to muffle the noise of the motor.

The other issue with pedestal pumps is that they can usually only ever run for a few hours at a time. Most submersible pumps can run for 24 hours a day with no issue as the water helps to cool the motor and prevent the unit from overheating. Pedestal pumps have no way to keep the motor cool, which means they could overheat if they run for too long.

Determining which type of sump pump is best for your home isn’t always easy as it depends on a number of different factors. This is why we would always recommend consulting with a professional plumber to ensure that you get exactly what you need. At Anchor Plumbing Services, our team has years of experience installing, maintaining, and repairing sump pumps and can help ensure you get the right unit and that it works correctly. As a full-service plumbing contractor, we also install and repair water heaters, garbage disposals, water filtration systems, and all types of kitchen and bathroom plumbing fixtures. If you need drain cleaning or any type of sewer, water, or gas line services, we can help with that as well. Give us a call today if you have any questions or need any plumbing service in the San Antonio area.

company icon