Your pool pump needs to prime to keep the water flowing and prevent the motor from overheating. An unprimed motor typically has plumbing issues, but there are many other potential causes. Show
A pool pump that won’t prime has one of these issues:
In this post, I’ll discuss why your swimming pool’s pump won’t prime and why it needs to be repaired immediately. I’ll also explain the solution for each problem to help you fix your pump without hiring a pool technician (aside from two issues that require professionals). 1. Too Much Air in the SystemAir rushing into a pool pump will prevent it from priming. Here are the most common ways that air can flow into the pump:
How To FixHaving air in your pool equipment pad can wreak havoc on the system. Here’s what you should do:
2. Warped Pump ComponentsExcessive sunlight, failure to run the pump, and overheating can warp pool parts. If your pump won’t prime, it might be due to warped or misaligned lids, unions, O-rings, and plumbing. Check each of the unions before and after every piece of equipment. Look for bent or warped plumbing because it lets water flow into the gaps. How To FixUnfortunately, warped pump parts can’t be repaired; They have to be replaced. Swim University shows the sun’s UV rays, constant usage, and long-term operation can wear down a pool pump. It can also take a toll on the heater and filter, so those might also need to be replaced if they’re inviting air into the system. The good news is that you can replace each part before getting a new pump. For example, if the lid is broken or warped, all you have to do is get a new lid from the manufacturer. All pool pump parts should come directly from the company rather than a generic brand. These components are specific to the make and model, so they can’t be substituted or replicated. 3. Not Enough Water in the PoolIf there’s not enough water in the pool, your pump will pull air into the basket, motor, and filter. A lack of water can be caused by evaporation and leaks. It’s essential to keep the pool water above the highest inlet at all times. When the water moves from swimming and splashing, it can pull air into any exposed inlet. How To FixIf your swimming pool doesn’t have enough water, we suggest following these two tips:
4. Demanding Pool VacuumsSome pool vacuums use electricity, while others require suction from the pool pump. If your vacuum uses the pump’s suction, you’ll need to increase the RPMs. Without enough RPMs, the suction will be weak and won’t prime the pump. Furthermore, the vacuum hose can push upward and suck air into the line. How To FixPool vacuums demand more RPMs, so it’s important to know if your pump can handle the pressure increase. You can get a booster pump if you have a pressure-side pool vacuum. I recommend the Polaris PB4-60 Booster Pump, as it provides enough pressure to propel your pool vacuum without taxing your main pool pump. Not only does it make your vacuum much more efficient and effective, but it also increases your pump’s longevity. You can run your main pump without worrying about the vacuum ruining its prime or suction.
5. Skimmer Clogs and BlockagesSkimmers are prone to clogs because they prevent large debris from entering the pump. If the debris flow is too much, the skimmer’s gate can jam, slowing the water and stopping the prime. When the water can’t enter the pump’s inlet, it drops the pressure immediately. Wear and tear, corrosion, and chipped hinges can jam the gate. How To FixI suggest cleaning your skimmer basket as often as possible. All of the leaves, twigs, hair, and other debris that fall into your pool goes to the basket. This debris clogs and breaks the basket if it’s unchecked. Most pool owners should clean the basket every two to three days. If the skimmer gate is blocked or jammed, check the hinges. These hinges can get brittle and dry in their slots. They need to be replaced once they’re too brittle. Much like all other swimming pool parts, you need the exact measurements to get the correct gate. Otherwise, it won’t fit. 6. Broken PVC PlumbingIf any of the pipes in the plumbing are broken, cracked, or leaking, your pump will have a tough time priming. In fact, large cracks will stop the prime, preventing it from starting at all. Your pump will roar and pull air, frying the motor. Tree roots, direct sunlight, poor chemical maintenance, and many other factors can contribute to broken plumbing. How To FixPVC plumbing needs to be repaired as quickly as possible to prevent further (and more expensive) damage. Here’s what we recommend:
If you’ve never repaired PVC pipes, I highly recommend hiring an experienced swimming pool technician. It’s not an easy process, and mistakes can lead to costlier repairs down the road. 7. Debris in the Equipment PadMost pool equipment pads consist of a pump and a filter, but there are many other pieces of equipment that you can add. For example, there are salt cells, booster pumps, heaters, solar panels, and several valves on some pads. Trapped debris in any of these areas can limit the water flow and trap pockets of air in the line, stopping it from priming. How To FixFollow this quick step-by-step process:
If your pool still has pressure issues or won’t prime from excess debris buildup, you can hire a pool technician to blow the lines with a pressurized tool. 8. Unsealed Lids and UnionsPerhaps one of the most common reasons people can’t prime their pump is because the lid or unions aren’t sealed. This issue usually happens after filling the pump basket, removing debris, or switching the gaskets. Fortunately, it’s also one of the easiest problems to fix. How To FixUnsealed lids and unions take less than a minute to fix. Simply loosen each portion, align the O-ring or gasket, and tighten the lid or union. If there’s a leak from one of the unions or lids after you tightened it, you can try one of these tips:
Pool Pump Won’t Prime All the Way? Here’s What To DoDoes it always seem like your pool pump starts priming, then suddenly stops? Maybe the pump almost primes all the way, but it can’t quite finish. Whatever the issue is, the most common cause is undoubtedly air in the lines. Pool pumps, filters, heaters, and plumbing need to have nothing other than water flowing through them. Air bubbles will drop the pressure drastically. If your pump doesn’t prime all the way, check each of the unions and lids for leaks. There’s more than likely a leak somewhere. However, you might’ve not added enough water. All pool pumps need to be manually primed every time the lid is removed.
Pool Pump Won’t Prime Completely? Here’s What To DoIf your pump won’t prime completely, it’s best to start by opening the air relief valve. This valve is located on top of the filter. Stand away from the open spout and turn it to the left while the pump is on. This process will flush all of the excess air out of the system, filling the lines with water from the pool. Remember, you have to manually prime the pump with the steps above. Other reasons your pump won’t prime completely include:
Pool Pump Won’t Prime After Vacuuming? Here’s What To DoPool vacuums demand a lot of pressure from the pump. If you move the vacuum too quickly, there’s a high chance it’ll pull air into the lines. So, what can you do to fix a pump that won’t prime after vacuuming?
Your pool vacuum might require too much PSI from the pump. We suggest getting the previously mentioned booster pump (the Polaris PB4-60) to provide an additional booster. This pump will work with your main pump to stop it from losing its prime every time you run the pool vacuum. Pool Pump Won’t Prime After Backwash? Here’s What To DoSand filters and DE filters need to be backwashed every few months. This process removes the built-up debris, lowering the filter’s pressure. However, you might have an issue priming the pump if something goes awry. All pumps need to be primed after the filters are cleaned. Follow the steps mentioned above to prime your pool pump. Remember to fill the pump basket with hose water until it overflows, then seal the lid. Open the air relief valve on top of the filter to let out all of the excess air. Another issue could be the filter’s seal. All filters have a body or lid gasket. These massive gaskets can move around and get misaligned when they’re being cleaned. Turn off the pump and align the gasket and lid to prevent air from getting into the system. Note: Don’t forget to turn the multiport valve on all sand filters and DE filters back to the filtering setting. Never keep the multiport valve on the backwash setting when you’re running it through the swimming pool, or the pump won’t prime. Pool Pump Won’t Prime After Freeze? Here’s What To DoFreezing temperatures can cause severe damage to swimming pools. Not only can it crack the gunite, but it can also damage the plumbing, unions, O-rings, and equipment. Water expands when it freezes, which can warp the parts. If your pool pump doesn’t prime after a freezing night or day, you might have to hire a professional. They can look for small cracks. You can prevent this issue from happening by keeping the pump running at a low speed when it’s supposed to be freezing outside. The slight water movement stops it from freezing. Wait for the ice to thaw before running the pump. Frozen chunks of ice can rip through filter cartridges and pump baskets. Pool Pump Won’t Prime From Main Drain? Here’s What To DoIf your pump won’t prime from the main drain, it means there’s a crack in the plumbing between the drain and the pump. Pool pumps are rarely primed from the main drain these days. The drains are inefficient and don’t provide good circulation. You can also replace the main drain lid with a like-for-like model if you think it’s chipped or clogged. Another suggestion is to turn the valve in front of your pump away from the main drain. It’s always better to pull water from the skimmer than the drain. Look for a multiport valve in front of the pump and check for labels before turning the lever. Pool Pump Won’t Prime When Vacuuming? Here’s What To DoIf your pump won’t prime when you’re vacuuming, but it’s fine during normal use, you need a booster pump. Pool vacuums use a lot of your pump’s pressure. Some pumps aren’t designed to handle a vacuum’s demanding strain. The aforementioned Polaris PB4-60 Booster Pump is the top choice for reliability, functionality, and affordability. Look for floating hoses. These hoses should be underwater if there’s no air in them. A floating hose is a clear indication of air in the lines. Open each hose, push it underwater, and let water into it. Pool Pump Troubleshooting ResourcesIf you have any other issues with your pool pump, check out our other pool pump troubleshooting articles: |