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

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.

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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.

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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.

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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.

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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 replacement sump pump float ball. Click Here

Wayne float kit for sump pumps. Click here

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.

Universal float switch can be added to a manual sump pump or potentially replacing a failed float switch. Click Here

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 Tethered Float Switch with 10 ft. or 20 ft. cord. PumpSpy brand. Click Here

Universal Piggyback Float Switch for up to 13 Amp 1/2 HP sump pumps. Check the price.

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