Sump Pump Keeps Running On and Off

sump pump running constantly

Sumpthing to Think About

To paraphrase an old, very old joke, you get a phone call and someone asks, “Is your sump pump running?” And if you answer, “Yes,” the caller says, “Well, you better go catch it.”

Okay, it was slightly funnier when you were 12, but there’s nothing funny about a sump pump running constantly. Because it means that there is something wrong with a sump pump if it is constantly running on and off.

Sump pumps generally run in intervals, as needed. But sometimes they run continuously, increasing electricity costs and causing them to wear out much faster than they should, and possibly even burning out the motor.

As with all types of mechanical devices, minor malfunctions happen. By doing regular inspections to ensure all parts are working properly, you can avoid bigger, unexpected issues down the road.

In this post, we take a deep dive into:

    • Why you need a sump pump
    • How a sump pump works
    • Reasons why a sump pump keeps running on and off
    • Possible fixes a sump pump that keeps running on and off

Why You Need a Sump Pump 

The purpose of a sump pump is to move water out of a basement. Of course, normally we don’t have water in the basement. Unless there’s a flood. Or, in some cases, heavy rainfall and a bad slope that allows water to run down and into your cellar. 

Even if you don’t have a finished basement, things can still get ruined with water in the cellar or crawlspace, so the sump pump is there to get rid of it in the event you have a flood or a heavy rainfall seeps in.

But unless there is a high level of water, the sump pump is normally off and shouldn’t be running.

How a Sump Pump Typically Works

Most common sump pumps are submersible, sitting in a liner, also sometimes called a basin, set in a sump pit that has a gravel base dug into the corner of the basement or crawl space. 

The sump pit serves as a drain for any water that might leak in. But when the pit can’t drain fast enough, because water is rushing in too fast, the water rises within the liner and fills up into the pump to the point where the pump’s float valve is activated. When that happens, the sump pump kicks in to push excess water out into a discharge pipe that leads out of the house foundation to somewhere outside. Because the discharge pipe is installed below grade, it is pitched upward, so that normally gravity would let the water flow back in. To prevent this, a check valve prevents any water in the pipe from flowing back into the pit and possibly back into your basement.

Why a Sump Pump Keeps Turning On and Off

Here are a few reasons why a sump pump may keep running:

    • The float switch gets stuck in the “on” position. 
    • The float switch gets pinned to the side of the liner and can’t operate properly.
    • The sump pump’s check valve may not be working properly or is broken. If the check valve is malfunctioning, the water it normally discharges into the outlet pipe washes back into the sump pit, thus reactivating the float valve and the pump. This causes your sump pump to continue working.  
    • Your sump pump or your liner isn’t the right size. If the pump is too small or insufficiently powerful, it has to work continuously to remove water that rises in the liner. Similarly, if the liner is too small, it fills with water more quickly, causing the pump to work more frequently. 
    • The sump pit is dirty and filled with debris. The sump pump sucks up that junk and its mechanical parts become clogged and dirty, and consequently don’t work properly.
    • In some cases, there is a high water table or underground spring that is feeding water continuously into the sump pit.

Possible Fixes If Your Sump Pump Runs Continuously

If your sump pump won’t shut off, the first place to look is the float switch. Follow these steps:

    1. Open your sump pump.
    2. Check to see if the float switch is pinned against the liner.
    3. If it’s pinned, untangle it so it can easily move with the water level.
    4. If you find that it’s not tangled and it can in fact move freely, it most likely needs to be replaced. You can purchase one at a hardware store or online.
    5. Unplug the old switch and remove it. Replace it with the new switch.
    6. Use a plastic tie (or any other tie that’s rot-resistant) to attach the new switch to the sump pump. This ensures it can float up and down with the water level.

What if the float valve seems to be working okay? Well, if it’s an old sump pump—older than 7-10 years— you probably need to replace it. Particularly if you see rust around the base, it’s useful life has probably expired. 

If there’s a lot of debris in the sump pit, clean it out. Unplug the sump pump, clean away any dirt the best you can. Turn it back and see if it operates better, which is to say, the sump pump isn’t constantly turning on and off. 

When to Call a Professional Plumber

If you’re not sure what’s going on with your sump pump constantly turning on and off, and you’ve either checked for the common problems we’ve noted, or aren’t confident you know what to look for, you need a professional plumber. The one thing you don’t want to do is ignore it and hope it goes away. You don’t want to be away from home when the sump pump fails when flooding occurs, because then you’re going to come home a pool in your basement.

It’s important to call a professional plumbing service to properly inspect and perform any required repairs your sump pump may need. With decades of proven expertise and customer satisfaction guarantees, Benjamin Franklin Plumbing Bay Area is happy to help you fix the  problem that your sump pump won’t stop running.

Wel always perform a thorough inspection first, and then we’ll provide you with a written estimate before beginning any work to ensure it fits within your budget. Once you give us the green light, we’ll get moving to get your sump pump back in shape.

Call us today to set up an appointment!