Sump Pump Keeps Running Constantly? Why? What Must I Do?

(Last Updated On: November 22, 2023)

When a sump pump keeps running there is a problem that must be fixed. The longer homeowners wait, the more expensive it is going to be. Not only will the sump pump motor burn out, but the house can be flooded. A flooded basement can cost tens of thousands of dollars to clean up and repair.

Sump Pump Keeps Running Constantly? Do This First

Check the float to see if it is functioning properly. The float turns the sump pump on and off. Is the float stuck in the up position?
There are two types of sump pump floats:

First, a tethered float that is at the end of a cord. This float hangs downward and rises as the water level rises. However, sump pumps can vibrate and move the pump sideways. This can pinch the float against the sump pump basin. Resulting in the float being unable to move lower and shut the pump motor off. Next check to see if the float is tangled up with the electric power cord.

Here is a budget priced sump pump with a Tethered Float Switch. Superior Pump 92570 1/2 HP

Superior Pump 92570 1/2 HP Thermoplastic Submersible Sump Pump with Tethered Float Switch
  • 1/2 HP Sump pump moves up to 3,300 gallons per hour; pump will lift water up to 25′ of vertical height
  • Tough thermoplastic construction; 10-foot cord length
  • Tethered float switch to automatically turn the pump on/off
  • 1-1/2 inch NPT discharge for high capacity pumping
  • Superior Pumps are Built to Last, engineered with quality components and are 100% factory tested

Second, the float is attached to a rod. As the water level in the sump basin rises and lowers, so does the float. Here again make sure the float isn’t pinched against the sump basin. Also, check to see if dirt is preventing the switch rod from moving downwards. Additionally, that float might get damaged and fill with water and preventing it from working. Although that would typically prevent the pump from turning on.

Next is the Best Overall Value submersible sump pump. WAYNE CDU790 – 1/3 HP

WAYNE CDU790 – 1/3 HP Submersible Cast Iron and Stainless Steel Sump Pump with Integrated Vertical Float Switch – Up to 4,600 Gallons Per Hour – Heavy Duty Basement Sump Pump, Black
  • Indoor Use Only – This 1/3 HP WAYNE basement sump pump is perfect to keep your basement dry during heavy water flow. Whether it’s rain, snow melting, etc. WAYNE model CDU790 can pump up to 4,600 GPH to keep your basement dry.
  • Tough And Durable – Corrosion-resistant epoxy coated steel motor housing and stainless steel fasteners come with a cast-iron volute that provides long life in tough sump pump applications.
  • Efficient Design – The top suction design eliminates air lock and minimizes clogging from any debris in the bottom of the sump pit. Easy to install in about 15 minutes with no need to drill a weep hole!
  • Additional Features – 1-1/2” NPT discharge for compliance with building codes. The vertical float switch has been tested to 1 million cycles for long-lasting use, up to 10 time more than our competitors.
  • Quality You Deserve – Proudly assembled in the USA for quality you can trust. Warrantied for 3 years for dependable, efficient, & ultra-quiet performance.

Step 2: Is the Check Valve Working Properly?

Without a check valve the water that remains in the vertical discharge pipe would flow back down into the sump basin when the pump turns off.

This would refill the sump basin and potentially make the sump pump to start up again. This is called “rapid cycling” or “short cycling”. Meaning that the sump pump turns on and off constantly.


If a check valve has been installed it may not be working. A blocked check valve won’t let the water pass through, which forces the water back into the sump basin.
How does a sump pump check valve get blocked? Sump water is very dirty. When the check valve closes there is about 8 feet of dirty water in the pipe above it. Some of the suspended dirt may sink and collect on top of the check valve. Eventually the check valve is unable to function.

Is the discharge pipe plugged up by dirt or ice? The check valve can still be working but a plugged pipe will prevent any water from leaving the sump basin.

If water can’t get out of the sump basin, pretty soon the basement will flood.

Be sure to get a Silent Sump Pump Check Valve that will let you sleep at night.

PumpSpy Silent Check Valve – 1-1/2″ with Buna-N Couplings, Model CV-150, Spring-Loaded Flapper, Sump Pump Life Expectancy Increase, Includes Steel Clamps Fit 1-1/2″ Pipe
  • QUIET OPERATION: Our sump pump check valve has a unique spring-loaded flapper that helps eliminate the water hammer noise that standard check valves produce. The water hammer noise occurs when the discharged water slams the check valve flapper down. This silent check valve can bring a quiet operation to your sump pump.
  • CLEAR VALVE BODY: This check valve will provide visibility to water movement. With the valve’s clear body, it’s easy to visually confirm that pumped contents are moving, the pipes are not clogged, and the pump in the basin is fully operational.
  • INCLUSIONS: Our silent sump pump check valve comes with stainless steel clamps and Buna-N rubber couplings for quick installation. The clamps and couplings fit a 1-1/2″ Schedule 40 pipe. Fits within a 5-1/8″ gap.
  • KEEP WATER OUT: This check valve is designed to keep pumped water within the discharge pipe from falling back into the sump basin. A fully functional sump pump check valve can increase pump life expectancy by preventing water from being pumped twice.
  • ABOUT US: PumpSpy provides sump pump systems that help eliminate the unknowns of a sump outage and prevents costly damage. We also offer Smart Sump Pump Systems that automatically track incoming data and check that a sump pump is working properly.

Step 3: Clean the Inlet Screen on The Sump Pump

The sump pump is actually pumping water out of the house, but the sump pump keeps running constantly? Chances are pretty good that the inlet screen is partially clogged up with gunk.
Pull the pump out of the basin and clean up the pump. This will permit the pump to operate at full capacity.

Step 4: Inspect the Sump Pump Impeller

A sump pump impeller looks something like a machinery gear or a fan blade. Over time it can be “sanded” away by all of the dirt it comes into contact with. Also, it can be broken by a rock that gets through the pump’s inlet screen.

A handy DIY person can usually replace the impeller. However, if the pump is more than about seven years old, consider buying a new sump pump.

Consider getting the Wayne Sump Pump Impeller Kit shown below.

Sale
Wayne 66059-WYN3 Utility Pump PC1 / PC2 Impeller Kit, No Size
  • PC1/ PC2 Impeller Kit
  • For Wayne utility transfer pumps
  • 90-Day

Sump Pump Constantly Running but The Basin Is Dry?

If there isn’t any water in the sump pump basin or not enough water to turn the pump on, what is the problem? The float is stuck in the upwards or “on” position.
Grab the float and pull in downwards. If that turns off the pump motor, then figure out why the float was stuck in the first place. If the pump continues to run the internal switching mechanism is faulty. It is better to just buy a new sump pump.

Sump Pump Running Constantly and The Sump Basin Is Full?

Use your hand to pull the float downwards to shut off the pump. If that stopped the pump then the pump is working properly (in most cases).
Check the backflow check valve to see if it is letting water pass through it. If it is not working, get it replaced.

In the meantime, the check valve can be removed and replaced with a temporary pipe section. This will let more water run back into the basin when the pump stops running. Which will make it operate more often, but at least the basement won’t flood.
If the check valve is working, go outside and see if the end of the discharge pipe is plugged. If need be, check for a plug inside the pipe between the discharge point and back to the sump pump.
Finally, it is possible that the sump pump is too small to handle the amount of water entering the sump basin. It is also possible that the pump is not functioning at its original strength. In either case, it is time to buy a new sump pump.

How to Repair “Sump Pump Keeps Running” Problems

Some manufacturers sell replacement floats such as these two from Wayne.

Wayne 60110-WYN1 Wayne Pump Certified Service Part, Black
  • Wayne Certified Replacement Part
  • Brand Name: Wayne
  • Product Dimensions: 4.0 X 4.0 X 4.0″
  • Country Of Origin: China
Sale
Wayne 60038-001 Float Kit For Cdu/Spf
  • Replacement FLOAT kit
  • Works with cdu and spf family of pumps
  • Easy installation
  • Does not include switch

However, if the switch has failed, a new float and switch can be added to the existing sump pump. Alternatively, consider buying a new sump pump.

Shown below is a Universal Float Switch that can be added to a manual sump pump or potentially replacing a failed float switch.

Superior Pump 92010 Vertical Float Switch , Black
  • Universal design works with many pumps; For use with sump and utility pumps
  • Non-mercury activated switch
  • 10-foot water resistant power cord with piggyback plug, Includes mounting bracket and clamp
  • 120-Volt maximum pump running current 10 Amp, RU, CSA Certified
  • Superior Pump’s Float Switches are Built to Last, engineered with quality components and are 100% factory tested

Several manufacturers make tethered float switches. They can be used to make a manual on/off pump into an automatic on/off sump pump.
These could potentially be used to replace a faulty tethered float. If the original tethered float is not activating the pump, these may solve the problem. However, if the switch mechanism inside of the sump pump is broken, even a new float will not work.

PumpSpy Sump Pump Tethered Universal Float Switch Replacement with Piggyback Plug for Sewage, Reliable Water Level Performance – 10 foot cord
  • HIGH-PERFORMANCE FLOAT SWITCH: Designed for maximum dependability, PumpSpy’s Tether Float Switch is made of gold-plated electrical connections that are resistant to accelerated pitting and wear. It detects changes in the water level and activates its automatic on/off function. 10 Amps @ 120VAC – Normally Open.
  • WIDE APPLICATION: This portable tool is a versatile float switch used with sump, sewage, or effluent pumps. It is intended for installation on the sump pump discharge pipe and helps provide a dependable and practical solution for automating your pump system.
  • UNIVERSAL REPLACEMENT: Have a replacement float switch ready when you need it the most! This universal replacement float switch will automatically activate your water pump. The float switch has a modular design and a 10-foot cord providing plenty of flexibility, while the piggyback plug helps to create a universal connection.
  • EASY INSTALLATION: Our Tether Float Switch for a sump pump comes with everything you need for a quick installation. It includes a hose clamp and a cable grip for easy adjustment. This switch is simple to install by attaching the hose clamp to the pump’s discharge line. Once connected to the discharge line, the pump’s power cord plugs into the piggyback plug, which is then connected to any 120V outlet.
  • PUMPSPY PROMISE: PumpSpy products are proudly assembled in Kalamazoo, Michigan. We employ patented, proprietary technology to help with your sump pump 24 hours a day, seven days a week. We are committed to consistently enhancing our goods, delivering quality and dependability, and providing our customers with peace of mind.
WaterBoss Sump Pump Float Switch – Universal Water Level Sensor with 10-Ft Tether and Piggyback Plug for Grinder, Septic Pump and Sewage – Honeywell Microswitch Rated for 1M Cycles, IP68 Waterproof
  • AUTOMATE WATER LEVEL CONTROL with the WaterBoss Float Switch for sump pumps, waste water tanks and septic pumps. Our tethered sump pump switch is a reliable alternative to a stem mounted float.
  • UNIVERSAL WATER LEVEL SWITCH with piggyback plug supports direct connection to motors up to 1/2 horsepower or 13 amps at 120v AC. This is for non-continuous pump operations and emptying use only.
  • 10-FOOT CABLE FLOAT SWITCH for water tanks and light to medium amounts of suspended solids is fully adjustable. The float reacts to liquid levels, shutting off the pump to prevent the motor burning up.
  • RUGGEDLY BUILT with non-corrosive polypropylene casing, self-lubricating armature and a Honeywell microswitch rated for over 1 million cycles, WaterBoss Sump Pump Switch has received CE and IEC approvals.
  • QUICK, EASY INSTALLATION and reliable, frustration-free water sensor monitoring make WaterBoss the ultimate water tank float switch. It comes with a 5-Year Warranty for your peace of mind.

Last update on 2024-01-24 / Affiliate links / Images from Amazon Product Advertising API

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