Why Does My Pool Pump Lose Prime?

The traditional pool pump features various unique components that should be functioning at optimal levels. However, while these components have to function at top levels, not many pool owners are well informed about these tools.

So, what do I need to know about a pool pump losing prime when vacuuming?

Well, there are several unique factors you have to take into perspective. For instance, you have to find the cause and ways you can use to remedy the issue. Once you are through, you should be in the right position to restore the pool’s functions:

What Happens When a Pool Pump Loses Prime?

There are a few reasons that could cause your pool to lose prime as you vacuum the pool. First when you connect the vacuum hose to the suction section, this could cause a strain on the pump. On average, expect the suction pipe to average at 20 inches long.

However, connecting a vacuum hose can significantly increase the total distance to 20 inches and higher. Such a level is higher than that of the vacuum. If you have an undersized pump, or one that has functionality issues – any additional pull might cause an excessive strain.

The other common issue would be that small pool pumps tend to be robust. So, you are likely to come across various defects on the vacuum hoses of the pump. These will let in air through the small cracks or structures in the pipe.

A common technique people use to solve this issue would be to remove one vacuum hose at time, to determine if the system starts priming. Furthermore, you can also hold each section manually, or completely under the water level.

Installing a vacuum to your plumbing system might cause a further strain on the pump, and can compromise the gasket structure. You may have to lubricate the gaskets and o-rings including the pump lid for this process.

Steps To take If Your Pump Is Losing Its Prime

If you have a handy toolbox around and some basic DIY knowledge into pools pumps, you can start the checking process. A few useful pointers to help get you started with the checking process include:

  • Check for leaks – a significant portion of all pool pump complications exist on the suction section. Any leaks on the intake line of the pump and shaft seal housing can compromise the pumps priming. So, check to determine all pipe connections are well installed in the housing, and that they are tight, and the intake line does not have any form of damage.
  • Valves – most of these pumps feature foot valves, which work to store water in the intake line when the pump is not functional. If there is any leakage in the foot valve, the pump may lose prime. So, you may have to replace any faulty valve to help stop the issue.
  • Obstruction – one key reason a pump loses prime is due to obstructions or blockages. Furthermore, issues such as debris in the suction strain is likely to be a leading cause of the issue. Any blockage in the intake line can also cause the pump to overheat. Such overheating issues will compromise the pump’s functions.

How Pool Pumps Work?

A pool pump features a motor that works to drive water through a filtration system based on specific time intervals. The traditional pool pump needs regular filling of water to avoid compromising its functions.

Using the pump when its dry can cause the motor to burn out, and you might have to replace costly parts. If the damage is excessive, you are likely to pay a large amount of money for repair applications. So, never run a pump dry, and ensure you prime it well before use.

What Does it Mean to Prime a Pool Pump?

The most notable issue with pool pumps is that they often get pockets of air inside the internal systems. Any time the pump works without water, such as when you close down the pool, its likely to suffer from these air pockets.

So, before you can use the pool pump in such conditions, you have to remove the air and replace it with water. Doing this is the process referred to as pool pump priming.

Why You Should Prime Your Pool Pump

The traditional pool pump is a costly component. You need if you want to maintain your pool, and buying one each summer can be inconveniencing. So, finding the right technique to prime the pool pump is a crucial step in ensuring the pump does not run dry.

So, using a pump when dry is more likely to lead to mechanical issues for the pump. So, you have to ensure you use the pump when it’s full of water. The best advice for you would be to evaluate it regularly for any issues.

Failing to do this process right is not suitable, and can easily compromise the longevity of your pump.

Steps to Prime Your Pool Pump

The steps in priming your pool pump are simple. A few common things to expect include:

  • 1. Switch off the pump. While the pump might already be off during this process, double-check to confirm if it’s off. You have to ensure to use the right safety precautions before you start priming the pool pump.
  • 2. Switch to recirculate. If the pump has a multi valve, you cen set it change the water circulation. Doing so will direct the water in the pump, and change its direction back to the pool. In this setting, the water passes through the filter, and flows onto the pump directly.
  • 3. Then proceed to release the air. You may have to remove the excess pressure by opening the air relief valve. It usually sits on the top section of your filter.
  • 4. The next step is to clean the basket in your pump. Ensure you remove contaminants such as debris that might accumulate in this section. Also, evaluate the pool pump for issues such as progressive damage.
  • 5. Proceed to fill the basket. Get a garden hose, and use it to fill the pump. Also, you place the lid on the pool pump.
  • 6. Once you fill the pump basket,  and secure it well, ensure you open the air release valve, and that you switch in the power.
  • 7. Evaluate the flow of water to the pump for any issues. The water should flow properly for a few seconds. However, if the flow is not consistent, switch off the pump and repeat this process.
  • 8. Once the water flows at a constant rate, ensure you shut the pressure release valve.


Why Does a Pool Pump Loses Pressure When Vacuuming?

A pool pump might lose pressure when vacuuming when there is a hole on the top hose section. If the hole is close to the surface, this issue will cause the pump to loose prime. Also, attaching the vacuum hose to this unit will also likely increase pressure in the suction.

Why Does my Pool Pump Keep Losing its Prime?

Any leakage in the intake line of your pool, or the shaft seal housing can lead to such issues. Furthermore, issues such as obstruction have also been common in pool pumps that have lost prime. The obstruction might be due to the presence of debris.

What Setting Should Pool Filter Be on When Vacuuming?

If you want to perform routine vacuuming, ensure the filter setting sits on the normal position. Doing so will help change the directions of the water as it moves through the pool filter. As the water moves through the filter, the contaminants remain and the water flows back through return lines.

Why Does my Pool Filter Have No Pressure?

Your pool does not have any pressure due to various issues. The first one would be that it probably has a clogged impeller, clogged pipe or skimmer. Furthermore, check to confirm if it has a broken valve as it’s a leading issue in pump priming.


If you are a pool owner, you probably want to find ways to stay informed about the functionality of resources such as the pump. While a pool pump has many different components, its easy to stay informed.

So, if your pool pump loses prime when vacuuming, you should realize that the issue could be due to various factors. So, be keen to ensure that you can identify such issues ahead of time.