How to Adjust Sump Pump Float Switch

Your sump pump float switch serves a vital purpose in a sump pump switch’s functionality. A float switch in the sump pump system is what triggers the sump pump when water levels have risen too high in the sump pit. In this article, we’ll explain this device and let you know how to properly set up and adjust your float switch.

Adjust Sump Pump Float Switch

How to Adjust Sump Pump Float Switch?

Adjusting a sump pump float switch isn’t overly complicated, but it does require an understanding of how a sump pump works. Additionally, because there are many types of float switches available on the market, you’ll need to understand the specific model and type that you are working with (i.e. check the instruction manual).

Generally speaking, adjusting a sump pump float switch requires you to disconnect the pump, adjust the float/float cord, test that the switch is working properly, and repeat until it’s perfect. It’s a simple yet precise process, and we’ll explain it in more detail below.

What is a Sump Pump Float Switch?

To understand a sump pump float, you need to understand how a sump pump works. A sump pump sits in a sump pit beneath your home and works to pump out any water that is drained into the sump pit from inside or outside your home. The sump pump “pumps” this water up and away from your home, preventing any basement flooding.

A float switch works to trigger the sump pump to turn on. When water is beginning to fill the sump pit, the float switch will trigger the pump, preventing any problems before they occur.

There are many types of float switches on the market, but just about every single one operates according to the same principle. A float switch has a component which “floats” in the water as the sump pit fills with runoff.

At a certain water level, this floating component triggers a switch, which turns on the pump itself. Different types of float switches might work differently – more on this below – but they all utilize some element of this design.

How do you Adjust a Float Switch?

Once again, adjusting your specific float switch may differ depending on the specific design. But generally speaking, adjusting a float switch will involve the same general process.

Use this guide, but also consult the instruction manual for the device itself. Here’s how to adjust a float switch to work properly:

Step 1: Turn Off Power to the Sump Pump – Turn off the power to your sump pump as a precautionary measure before you begin. This is always a good idea when working with appliances in your home. Either unplug the sump pump or turn off the breaker providing power to the device.

Step 2: Adjust the Float Switch/Cord – Your device will have some method of unfastening and adjusting the float cord. It’s usually very intuitive, but you might need to check the manual. Unfasten the connector holding the float to the cord. Then, you will be able to adjust the float cord to the proper length. Once you think it’s perfect, reattach the device.

How High Should the Water Level be in My Sump?

The proper length for your float cord is the length at which the switch will be triggered when water fills the sump pit to a certain height. Most plumbers recommend that the cord be installed to hang a few inches from the top of your pit.

This ensures the sump pump can turn on with ample time to drain the pit, but also that it doesn’t turn on every time the sump pit fills with water slightly. Of course, this also depends on the overall size of your pit and the power of your pump. You’ll need to use a certain degree of common sense.

Step 3: Pour Water into Sump Pit – Once you’ve properly adjusted your float switch, it’s time to test it out. Fill a bucket (or buckets) of water, and fill the pit to the point where you want the switch to trigger.

See whether the water actually triggers the switch to turn on. If not, turn on the sump pump to drain the water, repeat the process, and readjust. It can be a slightly tedious process, which is why you’ll ideally want to nail it the first time.

Step 4: Readjust Until Perfect – It might be the case you’ll need to repeat the process a few times to get it perfect. This is normal, and float switches can be finnicky. However, with practice, it will become much easier. And if you don’t want to worry, call a professional!

Types of Float Switches

There are many types of float switches you can buy for your sump pump. Each might operate with a different “float” component and a different method of triggering the switch. But all float switches operate with the idea of triggering the sump pump once the water has reached a certain level.

Vertical float switch

Generally speaking, the two main categories of float switch are electronic and manual. This refers to the method of adjusting the length of the float cord, so that the switch is triggered at the proper time.

A manual switch allows you to adjust the length of the switch by hand, or with a common tool, usually a screwdriver. An electronic switch allows electronic adjustment of the water-detecting elements of the device. In other words, you can adjust the electronic components so the float switch is triggered at different water heights. Different electronic float switches will have different methods of adjusting these variables.


Thanks for reading our guide to adjusting your sump pump’s float switch. It’s a relatively straight-forward process, but it does involve precision, and it can become frustrating if you can’t tell why your switch is not working as intended. For this reason, you may be tempted to contact a professional who can easily and readily identify and rectify your issue.

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