June 6, 2016

Sump Pump Float

Sump pump float is the part of the sump pump that tells the motor when to start working and when to stop. Many people have installed sump pumps at home in the hope that it would keep their basements water-free during dark, rainy months. However, a lot of these people have also experienced problems with sump pumps stopping without even knowing what to do. If this happens to you, the first thing you should check is the sump pump float.

Sump Pump Float

The Functions Of Sump Pump Float

Some people have the misconception that the sump pump float is a just a small and negligible component of the sump pump. On the contrary, the float is probably one of the most important parts of a sump pump system. If your float does not work, chances are your sump pump won’t as well.
Basically, a sump pump float determines when the sump pump should start working by using the water level in the sump pump pit as the indicator. You can think of the float as working in the same way as a ball which floats on water. Obviously when water level rises, the sump pump float will naturally rise along with it. This continues until it reaches a certain level whereby the sump pump alarm will then be triggered to work and drain off the water.

Types Of Sump Pump Float

A sump pump float is commonly found in three varieties: the diaphragm switch, a vertical float, and a tethered float.

A diaphragm switch is the most expensive but the most reliable sump pump switch available. This is used on submersible sump pumps where the entire system is immersed. The diaphragm is very sensitive, detecting water pressure and water level without the actual float. Here, the diaphragm becomes concave once water levels go up. As soon as water level goes down, the diaphragm returns to normal as well. The good thing about the diaphragm is it actually gets rid of having to rely on an actual float, so that you will not need to go through the unpleasant experience of a stuck sump pump float. Flotec sump pumps are a well established brand of pumps. Flotec sump pumps are used to protect properties from flooding and other water related damage.

The most common sump pump float is the vertical float. Basically, the vertical float looks much like the ones you see when you open the lid of conventional toilet bowls. A balloon-like item is connected to a rod and while the water level increases, the balloon floats higher up as well. Once the balloon reaches a specific height, it prompts the machine that it is now time to suck up the water. Once the balloon goes down and the rod decreases in height, the motor of the sump pump stops working as well.

Another common float connected to the sump pump system is the tethered float. Basically, the tethered float functions the same way as the vertical float, only that the balloon is attached to a more flexible cord instead of a rod. This allows for the balloon’s free movement and is often the cause for the float getting stuck. Tethered floats are usually the cheapest and offer the shortest warranty.

If you want to make sure that your sump pump works perfectly, it would be ideal to invest in a high quality sump pump float. Not only will it reward you with lesser maintenance, the longevity of its life span and the peace of mind it gives you are priceless as well.

Related Topics:

Sump Pump Drainage


  1. During a flood I watched one of these sump pumps throw hundreds of gallons per hour out of my neighbors yard. Wettest spring in years, and he chose to build his home near the river below the water table. It's a good thing the local sewer lines could handle the runoff.

  2. I did not know that the sump pump float was a very important piece of equipment. It is good to know that so that way the sewer pump needs repair. I'll have to keep an eye out to see if it is still working.

  3. What a great idea to explain the varieties of a sump pump float. The varieties are what I would probably start learning more about. It's because my brother talked to me about replacing the tank pump that is found in my basement.

  4. Excellent post. I read your article. it's interesting.

    Belt Conveyor