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Pool Pump Keeps Shutting Off? Here’s Why (+ How to Fix)

If your pool pump keeps turning off accidentally, your pool will grow algae and look gross. In fact, an uncirculated swimming pool can be a health hazard that leads to citations.

It’s essential that you fix your pump immediately to prevent unhealthy bacteria, mosquitos, and other pests from turning it into their home.

Your pool pump keeps shutting off for these reasons:

  • Clogged impeller
  • Capacitor issues
  • Overheated motor
  • Faulty timer
  • Tripped breaker or fuse

In this article, I’ll show you how to get your pump back to good condition. I’ll also explain why it keeps shutting off and how you can prevent it from happening. Enjoy!

Impeller Clogs

Your pump’s impeller pulls the water into the filter and other equipment. If your impeller is clogged by debris, it will overheat and turn the pump off. A clogged impeller will also hum and grind until it breaks the motor or trips the breaker.

Fortunately, unclogging an impeller is quite simple.

How to Fix

To unclog your pump’s impeller, follow these instructions:

  1. Turn off the pump and circuit breaker to stop the water from moving.
  2. Remove the pump lid and basket to access the impeller.
  3. Reach into the pump housing and remove the debris from the entangled impeller.
  4. If necessary, remove the retaining screws connecting the pump housing to the motor, removing the leftover debris from the impeller.
  5. Manually rotate the impeller to ensure it can move.
  6. Secure the housing to the motor, replace the pump’s basket, then seal the lid and prime the pump.

If you prefer a video tutorial, review this helpful guide from Clearly Seen on YouTube:

Bad Capacitor

A pump capacitor supplies power to the motor. This compact battery requires a solid connection to provide the necessary energy.

Once the capacitor fails, it needs to be replaced. A malfunctioning capacitor might let the pump turn on for a brief moment, but it’ll turn off in due time.

The only way to fix this issue is to replace the capacitor.

How to Fix

Here’s how you can replace the pump’s capacitor:

  1. Turn off the circuit breaker to prevent electrical shocks.
  2. Remove the capacitor’s cover from the back or side of the pump to expose the capacitor.
  3. Pull off the two wires connected to the capacitor, then remove the retaining screws.
  4. Install the new capacitor with the part number from the manufacturer, then seal the retaining screws.
  5. Attach the old wires to the corresponding nodes on the new capacitor, then seal the capacitor’s lid.
  6. Turn on the circuit breaker and test if the pump works.

Here’s a handy video that shows you how to short the capacitor to prevent shocks:

Overheated Pump Motor

An overheated motor will turn off the pump.

Some motors trip the breaker, whereas others have internal fuses that know when the motor gets too hot.

Overheated motors are caused by an excessive workload, so it’s important to find out what’s causing the motor to work harder than it should.

How to Fix

If your pump won’t prime, the motor will run dry and overheat.

Let’s discuss a few reasons your pump can overheat:

  • The pump isn’t primed correctly. Turn off the power, then fill the pump basket with water until it’s above the suction inlet. Turn on the pump and open the air relief valve on the filter until the water comes out, then seal it to finish priming the pump.
  • You might have to replace the worn, old motor. Turn off the power, disconnect the motor from the pump housing’s retaining screws, and remove the impeller with a screwdriver. Next, remove the wires from the motor, attach them to the new motor, and connect the motor to the impeller and pump housing. Prime the pump when you’re done.
  • The pump is running too often. Pool pumps need time to cool off between circulating the pool’s water. I suggest not running the pump longer than one hour per ten degrees Fahrenheit. For example, you could run the pump for 10 hours if it’s 100 degrees Fahrenheit outside.

Faulty Timer

Every pump has an internal or external timer that tells it when to start and finish.

A faulty timer could turn off the pump before it’s supposed to. Furthermore, the timer might trip the breaker if there’s a power shortage or loose wires. Replacing the timer will fix this common problem, so let’s dive into the solution below.

How to Fix

Turn off the power before replacing the timer. Remove the old timer by disconnecting the wires to the pump and breaker, then remove the retaining screws to the timer’s box. Then, follow these steps to install the new timer:

  • Try the Intermatic T104 Timer. This efficient pool pump timer is tried and true. Intermatic is the top pool pump timer brand available. This model includes timer trips and an efficient, user-friendly clock.
  • Attach the old wires to the new timer’s LINE and LOAD nodes, then attach the breaker’s wires to the back of the timer. Don’t forget to attach the green grounding wire to the timer, too.
  • Pull the clock outward, then rotate it to set it to the current time. Place the provided timer trippers on the desired ON and OFF times.

For a more detailed explanation of how to fix a faulty timer, read my guide on how to fix a broken pool timer.

Tripped Breaker or Fuse

Your pump won’t work if the fuse blows or the circuit breaker trips. A tripped breaker or blown fuse occurs when the motor overheats, or there’s an amp overload.

Too many amps from the pump, heater, and other pool equipment can trip the breaker, turning everything off. Check if the breaker has enough amps for the equipment, then try our suggestions below.

How to Fix

I have another article that explains the many ways to diagnose and repair a tripped pool pump breaker.

Breakers only trip when there’s an electrical issue. Never overlook a tripped breaker because it could cause permanent damage to the pump.

Here’s a brief explanation of how to fix the issue:

  • Turn off the power going to the breaker.
  • Ensure the pump doesn’t overheat, then check if there are too many amps going to the breaker.
  • If the breaker is overloaded with amps, replace the breaker or wire the pump to a more substantial breaker.

Additional Pool Pump Troubleshooting Resources

If you have any other issues with your pool pump, check out our other pool pump troubleshooting articles: