When your sump pump keeps running without stopping, the problem must be fixed as soon as possible. The longer you wait, the more expensive it will become to fix it. Not only can the house be flooded but the sump pump motor will burn out. If your basement gets flooded it can cost many thousands of dollars to repair and clean it up.
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If Your Sump Pump Keeps Running Constantly, Try This First
Sump pump floats come in two types:
With the first type, the tethered float is attached to the end of a cord. The float hangs down and as the water level rises, the float rises with it.
A sump pump however vibrates and this can cause the pump to move sideways, pinching the float against the basin. This will lead to the float not being able to move lower and the pump motor will keep running.
Also, make sure that the float didn’t get tangled up with the pump’s power cord.
Shown below is the budget priced 1/3 HP Thermoplastic Submersible Sump Pump with Tethered Float Switch. Superior Pump 92330.
If the sump basin is a bit too narrow, it might be possible to shorten the cord on the tethered float switch to stop the sump pump keeps running constantly. A more drastic solution is to get a bigger sump basin or a differt sump pump.
The next type of float is fixed to a rod. The float rises and lowers together with the water level in the sump basin. If the pump does not switch off, check that the float is not stuck against the sump basin.
Check that dirt isn’t stopping the switch rod from moving down. If the float gets damaged and fills with water, it will also not work any longer. That scenario would however result in the pump not turning on rather than it not turning off.
For a few bucks more get a longer lasting Cast Iron Submersible 1/3 HP Sump Pump with Vertical Float Switch. Superior Pump 92341 shown below.
Inspect the Check Valve to Ensure It’s Working Properly
Another cause of the sump pump keeps running constantly is faulty check valve. A check valve is required to prevent the water that stays in the vertical discharge pipe to flow back to the basin when the pump is switched off.
If this water does flow back, it would fill the sump basin again and could lead to the sump pump starting again. This is known as “short cycling” or “rapid cycling” and the sump pump will turn off and on continuously.
A sump pump check valve can get blocked in various ways. A check valve will close with around 8 feet of dirty water trapped in the pipe above it. Over time, the suspended dirt sinks and collects on the top of the check valve and this eventually results in the check valve being unable to operate.
Should the discharge pipe itself get plugged up with ice or dirt, this will block water from leaving the sump basin even if the check valve is still operating.
This will eventually lead to the sump pump keeps running constantly and the basement being flooded.
The Quiet Campbell Check Valve. Fits the standard 1.5 inch discharge pipe. The very popular see-through design lets homeowners see if the check valve is working properly. Shown below.
Clean The Sump Pump’s Inlet Screen
If the sump pump does pump water out of the basement but keeps running continuously, the problem may be that the inlet screen is partially clogged.
Removing the pump from the basin and cleaning the pump and the inlet screen will allow the pump to function at full capacity.
Check the Sump Pump’s Impeller
The impeller of a sump pump looks like a fan blade or machinery gear. It may over time be worn away by the dirt it encounters or can be broken by a stone that gets through the inlet screen.
If you are handy at DIY, you should be able to replace the impeller yourself. If your pump is however more than 7 years old, it may be worthwhile to rather buy a new sump pump.
Does Your Sump Pump Run Constantly Even though The Basin Is Dry?
If the sump pump runs without enough water to turn it on or if there is not any water in the sump pump, the float is probably stuck in the “on” or upwards position.
If the float is pulled downwards and this turns off the pump motor, try to determine why the float was stuck. If pulling the float downwards does not switch the pump off, the internal switching mechanism is likely faulty and it would be best to buy a new sump pump.
The Sump Basin Stays Full Despite the Sump Pump Keeps Running Constantly
If you pull the float downwards and this shuts the pump off, the pump and float are most likely working properly.
Check that the backflow check valve is allowing water to pass through it. Replace the valve if it is faulty.
While fixing or replacing the check valve replace it with a section of pipe temporarily. Although this will let some water flow back to the basin, leading to the pump operating more frequently, the basement will at least not flood.
If the check valve works properly, check if the end of the discharge pipe is not plugged. Also, check backwards for a plug inside the pipe between the sump pump and the discharge point.
It is also possible that the sump pump is not big enough to handle the volume of water that flows into the sump basin. Or that the pump is not operating at its optimal performance. In either case, it’s best to buy a new sump pump.
Repairing “Sump Pump Keeps Running” Problems
In a case where the switch has failed, a new switch and float can be fitted to an existing sump pump.
It may however be best to buy a new sump pump depending on the age of your existing one.
A universal float switch can be added to a manual sump pump or potentially replace a failed float switch.
Manufacturers often sell replacement floats like these universal float switches..
Piggyback Float Switches Turn Manual Pumps Into Automatic Pumps
These can be used to convert a manual on/off pump into a sump pump that switches on and off automatically.
This type of float may potentially be used to replace one that is faulty to answer the question: “What do I do if my sump pump keeps running”. A faulty switch mechanism inside the sump pump can however not be fixed by installing a new float.
Shown below is the WaterBoss brand Universal Piggyback Float Switch. It can be used with sump pumps up to 13 Amps and 1/2 HP
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Author at Best Sump Pumps
The first time I helped to install a drain tile and basement sump pump system was 1978.
Since then I have worked for a city water utility where I worked with and maintained pumps.
My rental properties and personal homes all needed sump pumps.
As a modular home dealer/builder, those new homes needed sump pumps.
I put that experience to good use by providing reliable, useful, and practical advice on buying, using, and maintaining sump pumps.