How to troubleshoot a circulating submersible pump that won't start?

Jul 14, 2025Leave a message

Hey there! As a supplier of circulating submersible pumps, I've seen my fair share of issues with these nifty little devices. One of the most common problems customers face is when their pump just won't start. It can be frustrating, especially if you rely on the pump for things like keeping your fish pond water circulating or filtering. But don't worry, I'm here to walk you through some troubleshooting steps to get your pump up and running again.

Check the Power Supply

The first thing you should do when your circulating submersible pump won't start is to check the power supply. Sounds obvious, right? But you'd be surprised how many times the problem is as simple as a loose plug or a tripped circuit breaker.

  • Inspect the Plug: Make sure the pump's power cord is securely plugged into the outlet. Sometimes, the plug can come loose over time, especially if it's been jostled around. Give it a gentle tug to make sure it's firmly in place.
  • Check the Circuit Breaker: Head over to your electrical panel and look for a tripped circuit breaker. If you find one, switch it back on. If it trips again right away, there might be a more serious electrical issue with the pump, and you'll need to call in a professional.
  • Use a Multimeter: If you have a multimeter, you can use it to check if there's power reaching the pump. Set the multimeter to the appropriate voltage setting and test the outlet. If there's no power, the problem could be with the outlet itself or the wiring in your home.

Examine the Pump for Blockages

Another common cause of a pump not starting is a blockage. Over time, debris like leaves, dirt, and small rocks can get sucked into the pump, preventing it from working properly.

  • Remove the Pump from the Water: Before you start examining the pump for blockages, make sure it's unplugged from the power source. Then, carefully lift the pump out of the water and place it on a clean, dry surface.
  • Inspect the Intake Screen: Most circulating submersible pumps have an intake screen that helps prevent large debris from entering the pump. Check the screen for any clogs or damage. If it's clogged, use a soft brush or a toothpick to gently remove the debris.
  • Check the Impeller: The impeller is the part of the pump that rotates to create the water flow. Sometimes, debris can get stuck in the impeller, causing it to stop spinning. Remove the impeller cover (if possible) and check for any blockages. If you find any, use a pair of tweezers or a small tool to remove them.

Test the Pump Motor

If you've checked the power supply and the pump for blockages and it still won't start, the problem could be with the pump motor.

  • Listen for a Humming Sound: When you plug in the pump, listen closely for a humming sound. If you hear a humming sound but the pump isn't starting, it could mean that the motor is getting power but there's a problem with the motor itself. This could be due to a faulty capacitor or a damaged motor winding.
  • Check the Motor Windings: If you're comfortable working with electrical components, you can use a multimeter to check the motor windings for continuity. Disconnect the pump from the power source and remove the motor cover. Locate the motor windings and use the multimeter to test them. If there's no continuity, the motor is likely damaged and will need to be replaced.
  • Replace the Capacitor: In some cases, a faulty capacitor can cause the pump motor to fail. The capacitor helps the motor start and run smoothly. If you suspect the capacitor is the problem, you can purchase a replacement capacitor from a hardware store or a pump supplier. Make sure to follow the manufacturer's instructions when replacing the capacitor.

Look for Leaks

Leaks can also cause a pump to stop working. If there's a leak in the pump or the piping, it can disrupt the water flow and prevent the pump from building up enough pressure to start.

  • Check the Pump Housing: Inspect the pump housing for any cracks or damage. If you find a crack, the pump will need to be repaired or replaced.
  • Examine the Piping: Check the piping connected to the pump for any leaks. Look for signs of water dripping or pooling around the joints. If you find a leak, tighten the connections or replace the damaged piping.
  • Test the Pressure Switch: Some pumps have a pressure switch that helps control the pump's operation. If the pressure switch is faulty, it can cause the pump to stop working. You can test the pressure switch using a multimeter or by following the manufacturer's instructions.

Consider the Water Level

The water level in the pond or tank where the pump is installed can also affect its performance. If the water level is too low, the pump may not be able to draw in enough water to start.

  • Check the Water Level: Make sure the water level in the pond or tank is above the minimum operating level specified by the pump manufacturer. If the water level is too low, add more water to the pond or tank.
  • Install a Float Switch: If you're having trouble maintaining the water level, you can install a float switch. A float switch automatically turns the pump on and off based on the water level, preventing the pump from running dry.

When to Call in a Professional

If you've tried all of the above troubleshooting steps and your circulating submersible pump still won't start, it's time to call in a professional. A qualified pump technician will have the tools and expertise to diagnose and repair the problem.

  • Contact a Pump Supplier: As a circulating submersible pump supplier, I'm always here to help. If you're having trouble with your pump, feel free to reach out to me for advice or to schedule a service call.
  • Look for a Certified Technician: When choosing a pump technician, make sure they're certified and experienced in working with circulating submersible pumps. You can ask for recommendations from friends, family, or other pump owners in your area.

Conclusion

A circulating submersible pump that won't start can be a frustrating problem, but with a little troubleshooting, you can usually get it up and running again. By checking the power supply, examining the pump for blockages, testing the motor, looking for leaks, considering the water level, and knowing when to call in a professional, you can keep your pump working smoothly for years to come.

If you're in the market for a new circulating submersible pump, I have a great selection of pumps to choose from. Check out our Fish Pond Small Submersible Pond Pump, Submersible Circulating Filter Pump, and High Power Fish Pond Submersible Pump.

4-2High Power Fish Pond Submersible Pump

If you have any questions or need further assistance with your pump, don't hesitate to contact me. I'm here to help you find the right pump for your needs and ensure it works properly. Let's get your water circulating again!

References

  • Grundfos. (n.d.). Troubleshooting Guide for Submersible Pumps. Retrieved from [Grundfos Website]
  • Franklin Electric. (n.d.). Submersible Pump Troubleshooting. Retrieved from [Franklin Electric Website]
  • Pentair. (n.d.). Troubleshooting Your Submersible Pump. Retrieved from [Pentair Website]