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Pond Pump Running But Not Pumping Water – Causes, How To fix

The pump is a “heart” of your backyard pond. It is responsible for creating the pressure that moves pond water, thereby providing fresh, oxygenated water to the plants and fish.

Therefore, when your pond pump stops pumping water, the fish, plants, and bacteria in the biological filter are at risk.

Pond Pump Running But Not Pumping Water Causes, How To fix

As with any mechanical equipment, your pump requires proper care and maintenance for it to function efficiently.

However, it’s not uncommon for pond pumps to stop working as they should even after maintenance service.

How can you detect possible issues, and hopefully fix them before contacting the installer?

Learning how to take care of your pond pump and even troubleshoot pump problems will go a long way to save you time and money.

You can hear your pond pump running, yet it’s not pumping water. What could be the issue?

Your pond pump is a piece of mechanical equipment like any other and isn’t immune to problems.

However, you’ll realize that the problems and issues that pond owners experience with pond pumps are relatively predictable, and can be fixed.

If your pond pump is running, but you can’t see the water moving, be sure to try to check for the following possible causes and fixes before contacting the manufacturer.

Possible Cause: There Is No Enough Water In Your Pond

One of the most common pump problems pond owners often experience is non-existent or diminished flow rate.

Remember, your pump can only push water if it has access to it. You, therefore, want to check to see if there’s enough water in the pond.

Low water levels in the pond can cause your pump to operate intermittently or pull in the air instead of water.

How To Fix:

The water in your pond will evaporate during the hot summer months.

This is a natural process. You must, therefore, establish the proper water level in your pond for the pump to function and work efficiently.

Make sure your pump has a continual water source.

Possible Cause: The Pump Is Vapor Locked?

The second possible issue could be that your pump is vapor locked. A vapor lock happens when the pond water being sucked by the pump changes to vapor as a result of reduced pressure.

The vapor gets trapped in the impeller chamber, thereby locking the water, reaching the suction nozzle leading to a loss in the Net Positive Suction Head (NPSH).

As a result, the Net Positive Suction Head (NPSH) becomes higher than the pressure at the pump’s suction nozzle.

Even though the impeller will keep spinning, it won’t be able to create the required pressure to move the water.

How To Fix:

The vapor so generated is trapped in the volute.

You can fix this problem by tilting the pump underwater to let the air bubble to escape through the inlet or outlet and allow for an upward intake of water.

Removing the pump from your pond and re-installing it can also help fix this problem.

Possible Cause: Pond Pump Blockage

If there’s a diminished or non-existent flow rate, yet the pump is running, your pump inlet or outlet could be having an obstruction.

An ill-placed twig or debris can affect your pump’s ability to push water effectively.

Water pumps are designed in such a way that they can handle small particles of debris. However, over time, these particles will accumulate and build-up, thereby affecting the parts inside the pump.

How To Fix:

Check to see if there’s any obstruction on the skimmer or intake. Check your pump filters as well.

Clogged filters will starve your pump of water.

If you can’t find any debris or obstruction in your pump’s pre-filter or skimmer, consider unplugging the pump before you can check for debris inside the pump from the outside of the pond.

You should also check the tubing for any kinks.

Once you’ve removed the debris from the inside of your pump, check if there’s any damage to the O-rings.

Note that the O-rings are one of the most critical parts, as they are responsible for sealing the pump.

When damaged, they allow debris to get inside the pond pump. You can easily replace them and get your pump working correctly again.

Possible Cause: Damaged Impeller

When small particles build up in the inside of your pump, they can damage or even break the impeller.

Your impeller requires regular maintenance and cleaning to work properly. Blockages often cause impellers not to spin, which is why you should make sure there’s no debris in the inside of your pump.

A worn-out or damaged impeller won’t pump water at full capacity. The fins on your impeller should turn 1800 before they lock.

If your impeller can spin through a full 3600 without stopping, you’re dealing with a worn-out impeller than needs to be replaced.

How To Fix:

First, start by unplugging and removing the pump from the pond. Follow your manufacturer’s maintenance guide to check for any debris blocking the impeller.

Remove any particles, sticks, and rocks that are lodged and trapped around the impeller.

If your impeller isn’t rotating at all, try to spin it using a pen or screwdriver manually.

If your impeller has not been in use for an extended period, likely, it won’t manually spin, in which case it will need to be replaced.

Pond Pump Running But Not Pumping Water – Conclusion

Pond pumps are essential to a clean and healthy backyard pond.

With a pond pump, the relaxing and peaceful sound of the water flowing over the rocks and the beautiful scenery wouldn’t exist.

When it stops pumping water, you may have a couple of hours to avoid a catastrophe.

Many times when a pond pump stops pumping water, there are a few things you can do to fix the problem.

The possible causes and fixes highlighted above are relevant to general maintenance and check that pond owners ought to follow regularly, especially when faced with this specific problem.

You must read and follow your manufacturer’s maintenance guidelines and user manual.

If you’re unable to identify or determine the cause of your pond pump problem, be sure to contact a pump repair professional or the manufacturer immediately.