How To Prime A Pool Pump: 3 Strategies (Sand Compatible)

There is an old saying that claims the two favorite days of a boat owners life are the day he gets the boat and day he sells it. This comical adage is often transferred over to the pool owner, although it is much tougher to get rid of a pool than a boat!

Funny as it may be, this cliche rings true for too many pool owners because they were not aware of how much maintenance a pool requires. Many new owners are not even taught how to prime a pool pump. Your dedication to the pool’s regular upkeep directly correlates to your ability to get use and enjoyment out of it.

Pool maintenance can typically be split into two main categories: Care for water pH and water filtering. Both of these large tasks rely on one single piece of equipment: the pool pump. Without this essential piece of machinery, your pool will come to a stop, and algae and bacteria will quickly develop. Pump maintenance should be first and foremost among your regular pool maintenance duties. Luckily, as important as it is, this critical gear really doesn’t require much advanced maintenance.

Keep the pool pump housing free from debris, lubricate the seal once per season, maybe clean out the pump basket if your skimmer misses a few pieces, and most importantly, keep the pump’s inside pieces wet. That’s about it for standard pool pump maintenance. When the pool pump goes dry, it’s not doing its job and is on its way to being damaged. This is why you need to know how to prime a pool pump.

Learning The Importance Of How To Prime A Pool Pump

Whereas most pool maintenance equipment is designed to withstand being wet from time to time, the inside of your pool pump is designed to be filled with water at all times. The motor spins an impeller that sucks water through the pump and part of the design is that by remaining in contact with the pool water it will naturally be cooled off as it spins. In fact, when the pump is being run dry it is being damaged by the building up of friction and heat. The seal on the lid dries out and eventually the motor itself can seize up and burn out. Keeping water in your pool pump’s pipes is essential for proper operation.

When you close the pool down for the season, you may drain the pipes and the pump itself of all pool water to protect it from freezing temperatures or becoming stagnant. Even if you don’t “close” the pool for a season if you live in a place that doesn’t see much of a winter, you can still get air inadvertently introduced into your pipes.

Leaks in the pool walls, excessive splashing, a small pool toy or ball blocking the skimmer, or just plain old evaporation can reduce your water levels. When it falls below the skimmer or water intake, you’re sucking in air. That air can become trapped in the pipes and build up over time. It’s possible for air to become cornered in your pipes even in small doses and continue to add up until it becomes a large enough air bubble to cause a blockage similar to vapor lock and stopping the water from flowing.

Once you see air in your pool pump’s chamber, it is time to stop the motor and prime the pump. Priming your pool pump is simply the introduction of more water to get that pump working, water flowing to your filter and cooling off the pump, and everything working so you can get back in the pool.


Techniques on how to prime a pool pump vary, but the ultimate goal is to get water flowing back through the pump’s line. The most direct and conventional technique is to feed the pump’s chamber straight into the pump itself through the removable lid. Before you can begin attempting any method, there are several common steps we need to take.

Turn off the pump’s electrical power. Running your pump dry does no good and will eventually damage the pump. You also want to turn off the power to eliminate the possibility of working with water on a hot electrical circuit.

Next you eliminate the filtration system. Turn your pump valve from “filter” to “recirculate”. We want as few variables as possible so we’ll prime the pump without the filter.

If you have an in-ground pool, you likely have an “input” valve that allows you to direct the incoming water from either the skimmers, the bottom drain, or both. Select a single source so we eliminate another variable. Above ground pools will not have this feature.

Open your air pressure relief valve. It will likely be near your pressure gauge. Once you open it you may hear the kiss of escaping air and watch your gauge bleed down to zero. This is good, the entire point of priming the system is to let the trapped air escape.

If you installed plugs in your skimmers, drain, outlet jets when you covered the pool for the season, be sure to remove them now. The same thing with the pump drain plug, close that up too.

These are all the common steps we’ll take in any priming attempt. Any one of these steps could lead to causing the pump to lose water and failing to achieve prime. Make certain we’ve covered all these steps and then we are ready to begin the direct approach of how to prime a pool pump.


For the direct feed strategy, we’re going to feed water directly into the pump’s main chamber. Remove the pump’s water chamber lid. This will be the clear piece where you see the water passing through the pump, and is commonly how you will be able to tell when your pump has lost prime by looking through this lid. Remove the lid and inspect it for cracks. While you have the lid open, this is a good time to inspect and lubricate the lid’s o-ring as well. A nicked or decayed o-ring, or otherwise compromised seal could be one of the ways excessive air is being sucked into the pipes.

Once the lid is off and set aside, be sure to pull and clear any debris from the pump basket. We want clear pipes with no obstructions while trying to prime the pump.

Fill the pump’s chamber with water. Let your hose fill the pump for a few minutes as hopefully it is also filling the pipes leading into the pump as well. Once the water has filled the pipes and pump and is overflowing the chamber, refit the lid and turn on the pump. You should see some bubbles and hear some sputtering as the air is pushed out of the pipes.

Flushing the air out will be a noisy act and you will hear gurgling in the pipes and bubbles shooting out of the jets. As long as water is flowing in the pump, the system is working and getting rid of the excess air. If you do not see water flowing through the pump, you may need to repeat the water filling process a few more times to really flush that air out of the system.

Once you see water running clear and fast through the pump, reset your source feed to “skimmer and drain” as appropriate, and move your filter selector back to filter. This may purge more air but as long as you don’t lose prime, this is a good sign. Once the air is fully out you’ll notice that air pressure relief valve is no longer hissing air but spitting water. Close it and jump back in the pool!


Another strategy on how to prime a pool pump is somewhat easier and can be used throughout the season as necessary. While opening the pump’s lid should be part of your annual maintenance routine, you can prime the pump without having go through all that trouble. If you lose prime occasionally throughout the season, you can feed water into the pump chamber by sticking a hose into your skimmer.

When a temporary clog such as a pool toy or a loss of water level causes your pool pump to lose prime, feeding the pipe plenty of water through the skimmer and forcing some water into the pump chamber can be a quick fix that won’t even require you to get out of the pool in most cases.


If you have a troublesome pool, maybe an aging system that through leaks and other problems causes you to lose prime on a regular basis, some pool owners have taken up another strategy on how they prime their older pool’s pump. You can have a inlet valve installed on your pump feed.

This amounts to nothing more than a valve that remains closed until you open it to fill with water. Think of it as doing the standard lid-off method without having to remove the lid and chance ruining the seal. Although, if your pool is losing prime often enough to install a specialty valve, it may be time to undertake some serious troubleshooting as to why…


Priming your pool pump should be an easy task that may require more than one attempt but should not take you all day to complete. If you can not get your pump to prime, consider checking for leaks in the water line, cracks in the pipes, damage to the pump lid seal, or a clogged line. In the case of the dual fed in-ground pool, switch the feed from skimmer to drain and see if the problem follows. There are plenty of steps you can take to see how your pool pump is losing prime but only a few reasons why it happens.

However, troubleshooting should be done so that you don’t lose prime too often and can enjoy more time in the pool.