Loud Pool Pump Humming Noise: How To Fix That Annoying, Eerie Sound

The sound of your pool pump humming is an annoying, eerie noise that you’re probably sick of hearing by now. What may not be as obvious to some people is how to fix this problem!

Vibration or noises from your pool pump are a clear sign of wear and tear on the unit. This usually indicates that a shaft has worn out, or there’s play in the bearings.

Unfortunately, even a brand new pool pump can have this same problem occur after only one season of use: from the vibration being too loud or squeaking while in operation. There are a few different reasons for humming pool pump noise. Yet, one of the most common is that your pump has been damaged with time.

Internal blockage


An internal blockage happens when debris and other items accumulate in hard-to-reach places. This usually happens when the skimmer is clogged by leaves, or the opening for the skimmer basket becomes blocked with them. The pump can’t get water and debris out of your pool and starts to make these humming noises.

The most common way to solve this issue is by clearing debris from the pump. You should also unclog your skimmer baskets so that water can flow freely through them. You may want to invest in a skimmer net to make this job easier for you.

If you were able to clear the skimmer basket opening but the buzzing persists, your pump requires quick repair. This suggests that the impeller of the pump may have collided with an internal object while the pump was in operation, or that the shaft may be clogged with debris.

You should immediately replace this since it might not only result in humming noises but also reduce the purity of your water.

Pump impeller imbalance

A pump impeller imbalance occurs when one side of the turbine blades on a pump is no longer balanced with the other side. This can lead to unwanted noise, pump overheating, and bad bearings.

When the blade is not properly balanced, the pump will run very loudly, and possibly burn out its bearings. The impeller is what pushes water through your pool’s filter system. It needs to operate smoothly, so your pump stays stable throughout its entire lifespan.

Pump bearing problems

Vibration or noise from the pump could also mean that there is wear and tear on the unit, which usually indicates that there is play in the bearings. This can lead to a shaft that is worn out or possibly bent. Both cases require immediate replacement of the pump unit.

Most of the time, “bad” bearings can be easily identified. You can inspect if your pool pump is making any unusual noises while pumping water – such as a grinding sound, or if there’s any sign of oil leakage from the bearings when it’s off.

This uneven wear and tear will cause your pool pump to perform poorly over time – which could mean you’ll need to replace it sooner than normal. The most common solution for a noisy or vibration bearing is to remove the cover plate and check the bearings. If you see that they’re badly worn, or rusty you’ll need to replace the bearing assembly.

It’s not uncommon for bearings to become contaminated with dirt, algae, or sand particles which causes them to leak.

Even though it is often not too challenging to see a bad bearing, it is much preferable to have your pump serviced. Professionals can address the issue quickly and will have access to the appropriate bearings, which will help you avoid wasting time, money, and irritation.

Bent Pool Pump Shaft

A bent pool shaft can lead to the water pump making bad noises and malfunctioning. It causes a relatively high vibration of the pump.

Use dial indicators to see if the pump is out of balance or not. You can do this by pushing the shaft where you think it might be bent in one direction, and seeing if the dial increases or decreases that indicates that a certain part of the shaft is bent.

If bending is registered on the dial indicator, you should replace the shaft. Otherwise, the pump would not operate properly and would be a hazard for the pool.

Misaligned Shaft


Misaligned shafts are not too common, but they can happen to any pool pump. The shaft is what turns the impeller and this is responsible for all of the water movement in your pool.

If the shaft becomes misaligned, it will cause a lot of problems with your filter system and could even damage other parts of your pump. It is better to call a professional if you are experiencing a misaligned shaft because you do not want to cause more damage and have to replace your pump prematurely.

A professional should be able to register this problem with special measurement tools.

While the technician will be working on the misaligned shaft, he could also check on some other things in your filter system. This way, you won’t have to worry if there are other problems with your pool pump system.


Cavitation is when there is a bubble that forms in a fluid due to the reduction in pressure. This type of phenomenon happens, because at lower pressure, bubbles can no longer be stabilized by surface tension and droplets will form.

When the water is reduced, bubbles will be formed when pressure reduction happens. This could occur with any type of pump if there is not enough water, and the air is sucked in. When the pressure is back to normal and thus the bubble collapses, it displaces the water in a fast and powerful motion, which is why cavitation can damage your pump.

When cavitation occurs in a pump, it will cause an imbalance, vibrations, and loud sound. While the pump continues to work in these conditions, the impeller can overheat, starts to wear down, and could damage the bearings.

Pump Flow Pulsation

Pump flow pulsation is a disturbance in the flow of water through a pool pump. The pulsations can be caused by an obstruction, a lack of feed, or if the pipe feeding the pump is too narrow.

Pump flow pulsation can be heard in the plumbing line before it reaches the pump, and if you hold an ear to the piping, you should be able to detect that the pulsations are caused by a low-frequency sound. The sound will not be loud but it is distinctive. It resembles a flushing toilet or distant waves crashing on a beach.

The problem occurs when the flow of water through the piping is irregular in any way, such as when an obstruction gets stuck in the line. The irregular pressure will create waves that are amplified by the pipe walls and then turned into vibrations at the pump itself.

The result of these vibrations is that water will flow through the pump in a pulsating nature, and this causes wear on the impellor blades, other moving parts, and even the motor bearings. If you see an obstruction inside the pool such as leaves or twigs on the surface of the water, it’s important to remove them as soon as possible.

New Pump Noise

Some pool pumps are designed loud, and there is no way to reduce the noise. Other pool pumps are designed to be quiet. The manufacturers of those pumps have invested time and money into the design, and it shows.

If the pump is too big for your pool it can result in a noisy pump. Yet, if the pump is too small, it can result in a dirty pool. You need to find out what the manufacturer recommends for your pool size. If you live in an area with hard water, then a good quality filter will be needed as well.

When looking for a new pool pump, it is always better to check for the quiet ones even if they are pricier.

Final Thoughts

If you notice that your pool pump is making a humming noise, it may be time to do some maintenance. Pumps are designed with moving parts that wear down over time and can produce an eerie sound when they’re not well lubricated or if there’s wear in the parts.

Buying a good-quality pump will save you money in the long term. You can use it for years without needing to replace it.

Choosing an affordable pool pump could mean that you have to replace it often, and you might end up spending more than what you spent on a more expensive one.

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