A sump pump float switch is designed to manage the timing of a sump pump. The float responds to the height of the water within a sump pit, allowing the water to be transported out of it when necessary.

If there isn’t enough water within a sump pit, the pump won’t work properly, which leaves your basement at risk of flooding. This is why it’s important to know how to adjust a sump pump float switch safely and correctly.

You’ll learn how to adjust a sump pump float switch in this post. We’ve gone over the different kinds of sump pump float switches and the tools you’ll need for the process below.

How does a sump pump float switch work?

It’s important to know how a sump pump float switch operates before you learn how to adjust it.

Sump pumps lie within a sump pit located underneath your home. They transport any water which enters the pit away from your home. The sump pump pulls the water from its pit and forces it away from your basement to prevent flooding.

Float switches trigger the sump pump. As the water starts to enter a sump pit, the float switch automatically turns on to activate the apparatus. Most float switches work similarly, though they are available in a lot of different types.

Adjusting a sump pump float switch

Adjusting A Sump Pump Float Switch

A sump pump helps you control how much water enters and leaves your home. If you adjust a sump pump float switch incorrectly, the pump may not turn on or won’t begin pumping water at all.

You’ll need the following tools to adjust a sump pump float switch:

  • Rubber boots
  • Pair of gloves
  • Screwdriver
  • Flashlight
  • Bucket

Once you have your tools, follow these steps to adjust a sump pump float.

Switch off power

This is an important safety step to take when engaging a sump pump. Water and electricity can lead to serious electric shocks, so it’s important to take care to avoid electrocution.

Make sure that the breaker box has been switched off or that the extension cord is disconnected.

Fixing the float

Now you’ll need to either electronically or manually modify the float switch.

If your float is manual, you’ll need to take off the cover plate from the sump pump’s base, then loosen any screws securing the float switch in position. After it is loose, raise the float upwards and downwards until the switch triggers the pump.

In the case of an electronic float, you’ll need to open the access panel with the electronic switches, and then select the switch with the best setting.

Once you’ve modified the float, ensure that it remains in the place you’ve set it. Avoid the float moving back into its previous spot when you test it. If it moves, you’ll have to reset the float once more.

Manual adjustment

Manually adjusting a float switch is usually easier than doing so electronically.

All you need to do is remove the cover plate as the base of the pump, then use your screwdriver to loosen the screws that secure it in position. Raise and drop the tether or rod based on the water level in the pit.

Electronic adjustment

Electronic float switches can be adjusted by modifying a screw that influences settings within the pump.

Every turn of a screwdriver lifts or drops water-sensing circuitry in the sump pump. If water comes into contact with these sensors, the pump triggers and operates until water levels fall under the sensors.

Water testing

After you’ve set your float switch properly, you’ll need to test it to make sure it works.

Connect the pump to power again, then test it by using buckets of water to imitate rainfall. The pump should activate as the water level increases, continuing to operate until it’s just about empty.

Readjusting the switch

If your float switch is still at the wrong level, disconnect the power and readjust it. The majority of systems need to be modified one more time, at minimum, to position the float at the right level.

How high should a float switch reach inside a sump pump

How High Should A Float Switch Reach Inside A Sump Pump

If you want to modify and fix a sump pump float, you’ll need to understand the best height of the float switch.

The best length for the float cord is the one that triggers the circuit; once water enters the pit at a particular point.

The cord should have some inches left at the top of the pit. This allows the pump to work properly, but not needlessly as the mechanism drains the pit.

It’s important to have the float switch at the right height, but this may involve trial and error before it works out. To work properly, the float switch should activate the pump when the water level increases to roughly five inches high.

Different kinds of float switches

It’s a good idea to know about the different kinds of float switches that may be used in a sump pump.

These switches are available in a lot of different types. The most popular ones are electronic and vertical models.


A vertical float switch has a float that weighs less than the water. This is linked to a pipe and connected to a power supply.

As the water level increases, the float travels up the vertical shaft it’s linked to. After the float gets to the top of this shaft, it pushes the switch to activate the pump.

This button can be raised or lowered along the discharge conduit by modifying the pole length that’s fastened to the float.


An electronic switch is linked to a discharge tube. Rather than a free-floating element that assesses water level, an electronic field determines this. The pump will activate if the water level lies within two lines on the switch.

You can adjust this electronic float switch in the same way as a vertical one. Either lower or raise the button based on the water level you want.

Final thoughts

Sump pumps are important to defend your home against flooding. They direct water away from your house instead of it accumulating within.


Save time and $$$ with a no obligation quote from recommended plumbers nationwide. It takes just 30 seconds.

Like any device, sump pumps may fail occasionally. If your sump pump float switch needs adjusting, always turn the power off before working on it.

You’ll be able to fix a float switch yourself, but if you experience any serious problems, don’t hesitate to call a professional plumber near you.