Zoeller Sump Pump Troubleshooting

Zoeller Sump Pump Troubleshooting

This is a complete guide on Zoeller Sump Pump Troubleshooting, where I will describe common Zoeller sump problems, including: 

  • Pump won’t start or run
  • Motor overheats & trips overload relay or blows fuse
  • Pump starts and stops too often
  • Pump won’t shut off
  • Pump operates but delivers little or no water
  • Tank or fittings leak

In short, you will learn everything about the common problems of Zoeller Sump Pumps and their solutions as well.

Without further ado, let’s dive in.

Table of Contents

Zoeller Sump Pump Troubleshooting [5+ Common Problems & Solutions]

Let’s jump into the problems directly and discover the solutions. 

1. Pump Won’t Start or Run

The Zoeller Sump Pump you own won’t start or activate if: 

  • The fuse doesn’t work as it should be
  • Low voltage
  • Overload relay gets tripped
  • Incorrect wiring
  • Impeller or seal gets bound
  • Defective or shorted motor 
  • Switch gets damaged or goes out of adjustment

How To Fix: 

You must address and resolve those issues if you want your sump pump to turn on to dewatering again. 

Fortunately, I have already covered a complete guide on Zoeller Sump Pump Won’t Turn On. Check that article out to learn the troubleshooting procedure to fix that issue. 

2. Motor Overheats & Trips Overload or Blows Fuse

The sump pump will overheat and trips either the overload relay or the fuse because of the following reasons: 

  • Incorrect voltage
  • Negative head impeller or seal gets bound mechanically
  • Motor gets shorted electrically 

How To Fix: 

As mentioned earlier, incorrect voltage can cause the motor to overwork. That’s why the first thing you should check is the power source of the sump pump. Verify the power source is capable of handling the motor’s voltage requirements. 

Ensure you don’t use an extension cord too long or too light as it will fail to deliver sufficient voltage to your sump pump motor. 

Needless to say, call a certified electrician if you are not electrically inclined to handle this matter.

For a bounded negative impeller or seal, I highly recommend you to call your plumber to inspect and fix the impeller issue. 

Thirdly, replace the sump pump itself if the motor gets electrically shorted or damaged. 

3. Pump Starts and Stops Too Often

Your sump pump will turn on and off constantly if: 

  • Float switch tether length is too short
  • Check valve gets stuck open or you don’t install it in long distance line
  • Sump pit is too small 

How To Fix: 

Each sump pump, especially that comes from Zoeller, has a tethered float switch to turn on and off the unit. 

It is such a switch that has a floating element, lowering and rising with the water level in the basin. If the length of the float switch tether is too short, it will struggle to create some arcs to actuate the switch. 

Consequently, the pump will come on and off continuously. 

To resolve this issue, I recommend you to adjust the float switch tether length correctly. Fortunately, BOSHART has an in-depth guide on Setting The Tether Point And Tether Length On A Sump Pump Float Switch. 

Read that article and adjust the float switch tether length properly. 

Or, you can watch this tutorial: 

Secondly, inspect the check valve on the distance line and ensure it doesn’t get stuck or broken. 

If it gets broken, the water will discharge into the outlet pipe and wash back into the sump pit. In this way, it will activate the float switch and turn on the sump pump.

In this case, replace the check valve with a new one. 

And lastly, a too small pit fills up with water very quickly and causes the sump pump to start and stop constantly. To resolve this issue, I recommend you consult with a professional plumber to size up the sump pit according to the pump capacity. 

4. Pump Won’t Shut Off

It’s a bit difficult to figure out the main culprit behind this issue as there are a lot of reasons that cause the pump to not shut off. 

However, one of common sump problems that can throw a wrench into work is the float switch. It’s the component that controls the power to your Zoeller sump pump. 

If the float switch gets bound by basin sides or other or debris under float assembly, the float switch will remain in the on position. As a result, your sump pump won’t shut off as the power goes to the unit continuously.  

How To Fix: 

Take your eyes at the float switch and verify it’s moving freely. The switch shouldn’t tangle up with the electric cord or against the basin sides or the side wall of the sump pit. 

If the float switch still won’t move up with the rise of the water, you should replace the float.  

When it comes to changing the float switch, I suggest you call your plumber to handle this as it’s a complex procedure. 

5. Pump Operates But Delivers Little Or No Water

Is the sump pump operating but pumping little to no water? If this is the issue you are experiencing, the following culprits are to blame: 

  • Obstructions in the inlet, strainer housing, discharge pipe, and vent hole
  • Discharge head exceeds pump capacity
  • Low or incorrect voltage
  • Air in the incoming water or air enters the pumping chamber
  • Incorrect motor rotation 

How To Fix: 

To begin with, inspect the inlet, strainer housing, discharge pipe, and vent hole for a clog. If you find blockage in the mentioned areas, remove the obstructions. 

Next, check the discharge head and verify the diameter of this pipe is equivalent to the pump’s discharge. If the diameter of the discharge exceeds the capacity of the pump, reinstall the discharge head according to the pump’s capacity. 

In addition, ensure the power source of the sump pump is capable of handling the motor’s voltage requirements. Also, make sure you use the right size of circuit breakers. 

Moreover, the sump pump will not pump water as it should be if the incoming water contains air. In this case, bleed the air from the pumping chamber or call a plumber for further assistance. 

And last, if the sump pump you have is a 3-phase pump, check the motor rotation. I highly recommend you to call a certified plumber if the motor rotation is incorrect. 

6. Tank or Fittings Leak

The tank or fittings will leak water if pipe joints and screws are loose. Turns out, loose lid or damaged gasket can even be the source of water leak. 

How To Fix: 

Check the tightness of the pipe joints and screws. If needed, tighten up the pipe joints & screws using the pipe dope. Also, ensure you tighten the lid evenly. Keep in mind; never over fasten up the screws and fittings.

How Do You Reset A Zoeller Sump Pump?

Zoeller Sump Pump has no reset button to reset the unit. It doesn’t mean you can’t reset your sump pump. Just locate the on/off switch and turn the unit off. Wait a few minutes and turn on the sump pump again. If this method doesn’t work for you, just unplug the sump pump from the electrical power source. After 30 seconds, plug the sump pump into the power source and it will reset your Zoeller Sump Pump. 


Q. How do you force a sump pump to turn on?

Just get your hand into the sump pump basin and press the switch until the pump engages.

Q. How do I know if my sump pump is burnt out?

The sump pump won’t come on if it gets burnt out. Sometimes the pump will make a loud noise due to a burnt out motor.

Q. How do I know if my sump pump is clogged?

It’s simple. Just verify whether your sump pump is pumping excess water or not from your home. If it’s not pumping water, I bet the sump pump gets restricted.

Q. Should I unplug my sump pump if it keeps running?

No, you shouldn’t unplug your sump pump from the power source if it keeps running on. If you want to unplug the sump pump, wait until the sump pit is dry. In general condition, never try to unplug your sump pump as it works as a safeguard of your home by defending the flooding events.

Q. How much should it cost to replace sump pump?

The cost associated with replacing a sump pump depends on the type of sump pump. If you want to replace a submersible pump, you should count $800 to $2000. However, the average cost of this pump is $1400. 

On the other hand, the range of replacing a pedestal sump pump is between $400 to $900, when the average cost is $650.

Q. Should there be water in my sump pump pit?

Yes, it’s normal to have water in the sump pump pit.


Well, I broke down all the common problems of a Zoeller Sump Pump. Try all the troubleshooting steps I mentioned and fix the issue you’re going through. 

However, if you are not mechanically inclined or don’t know what to do with your sump pump, it will be best to call a certified plumber. 

Good Luck!

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