ABC Blog

Pool Pump Won’t Prime: What Is Going On?

A blue pool with a pump that isn't priming

Pool pumps are supposed to make it easier for you to keep your pool beautiful, clean and ready to enjoy with family and friends. However, when a pool pump won’t prime correctly, it can spell disaster at the worst possible time.

Priming is the process of creating a vacuum effect so the pump can pull water out of the pool, pass it through the filter and push the filtered water back into the pool. When this process fails, pool water can quickly become dirty, cloudy and overrun with algae and bacteria.

Some common issues that can prevent a pool pump from priming correctly include:

  • Air in the pool pump
  • A dirty pool pump impeller
  • Low water pressure
  • Pool pump leaks

When your pool pump won’t prime, the best way to save time and money is to call a swimming pool repair expert. A professional can identify and fix most of these problems quickly and help prevent future issues, so you don’t have to waste valuable time trying to figure out what’s wrong. If you decide to try to tackle the issue yourself, keep on reading to learn more about your pool pump and other issues that may keep you poolside instead of enjoying a refreshing swim.

A swimming pool with brown tiles

How To Get Air Out Of A Pool Pump

If there is air in the pool pump chamber or intake line, your pump can’t prime or create enough suction to properly pull water through the filter and back out to the pool. Several issues can contribute to this problem, but there are some basic steps you can take to try to resolve the issue:

  • Turn the power off. Before you work on the pump, be sure the power is turned off for both the pool pump and your pool heater.
  • Adjust your valves. Turn the air relief valve to the open position, close the skimmer valves and make sure the main drain valve is open.
  • Inspect the pool pump strainer. Open the pool pump strainer box and remove any debris you find in the pre-pump strainer. If there is no water in the strainer basket or the water level is low, fill the basket with clean water to just above the strainer’s intake port.
  • Check for cracks. Look at the pump cover gasket to see if it is cracked. If so, you might need to replace it. If not, coat it with a silicone-based lube to improve the seal and reduce future cracking. Replace the pump cover and gently close it.
  • Test the system. Make sure the filter multiport valve is set to the “filter” setting and turn the power back on for the pump. As you gradually open the skimmer valve, you should see bubbles in the pool water as air clears out of the lines and hear air escaping through the air relief valve. When water starts to spray out of this valve, turn the valve to close it.
  • Do a final check. Water should now be flowing freely out of the pool pump’s strainer lid and filling up the pump’s strainer basket. If so, you can turn the power back on for your pool heater.

If water still isn’t flowing properly, you might need to repeat these steps to get all the air out of the line and get the pump to prime. However, if it still isn’t priming after you’ve gone through this process a few times, your pump might have another issue and it may be best to contact a pool service specialist.

Another common pool pump problem that can cause headaches is having a dirty pool pump impeller.

A blue pool with two sun bathing chairs

How Do I Clean A Pool Pump Impeller?

When the impeller is dirty, the pool pump can’t create the vacuum necessary for the pump’s filter process. The pump strainer basket is usually able to trap most debris and keep it from clogging the impeller. However, a number of smaller items can escape the strainer, including seeds, pine needles, pebbles, flowering tree stamens, pieces of pool plaster and grass.

You’ll likely notice a few clues that your pool pump impeller is clogged. For example, your pump might make a loud grinding noise or your pool pump may start humming, but not working. You may also start to see the pump strainer basket not filling up with water, or the filter pressure and water flow lower than normal. If you find any of these signs of a blockage, cleaning the impeller might help.

Here are step-by-step instructions to clean your pool pump impeller:

  • Turn off the pump. Turn off the electricity to your pump at the breaker, not just at the timer. This prevents the pump from accidentally turning on while you’re working on it.
  • Locate the impeller. The impeller is behind the pre-pump strainer basket. To reach it, remove the pump cover and the strainer basket. The impeller is located in the tube between where the basket sits and the pool pump.
  • Dislodge debris. Use your finger or small wire to clean out any debris you can feel in the tube in front of the impeller. Bend the wire with pliers, so you have a small hook at the end and another bend of about six inches, so you can better maneuver the wire. Insert the wire into the tube in front of the impeller and swirl it around to dislodge debris into the area where the basket normally sits. Once the debris is free, scoop it out with your hand.
  • Check the system. Replace the pool strainer basket, fill the basket with clean water from a garden hose, replace the pump cover and turn the pump back on. Water should start flowing freely through your system and the grinding sound should stop. If problems continue, you might have a bad impeller or other pump issues that can be better diagnosed by a certified pool specialist.

Another scenario that can cause problems is when your pool pump is not be working as it should because your water pressure is too low.

A swimming pool and two Adirondack chairs

How Can I Tell I Have Weak Water Stream Or Low Pool Pump Pressure?

If you’ve noticed water coming out of your pool’s jets or water features with less force, your pool cleaner running more slowly than usual or air bubbles coming out of nozzles in the pool, then you might have low pressure. When this happens, your pump can’t work correctly. If ignored over time, low pump pressure can damage your pool system and cause algae and bacteria build up in your pool water, which often needs to be fixed with expensive chemicals. If you think your pool system has low pressure, there are several factors that might be causing it and how to address them, including:

  • Low water levels. Make sure the water in your pool reaches at least halfway up the opening of your skimmer doors. If the water level is low, use a garden hose or the valve that fills the pool with water to fill it until water reaches the correct level.
  • Dirty strainer and skimmers. Remove debris from the pre-pump strainer basket and skimmer baskets.
  • Clogged filter. Your pump pushes water through a filter before it goes back into your pool. When the filter is clogged, it can disrupt your whole system. If you’re wondering how to clean your pool cartridge filters, the answer will depend on what type of filter you have. You can lay cartridge filters out on your lawn and spray them down with a hose. However, this won’t completely remove grease buildup from sunscreen, oils released by human skin or plant substances. The best cleaning method for an accumulation of these materials is to soak the cartridge overnight in a chemical made for pool filter cleaning, such as a TSP solution. If you have sand filters, use the backwash cycle regularly to clean these important parts. Keep in mind that the sand in your filter will need to be replaced from time to time to keep your filter working properly. A pool and spa professional will be able to determine how frequently your sand should be replaced.
  • Blocked impeller. To unblock the impeller, use your finger or a small wire to remove debris from the tube between the pre-pump strainer basket and the pool pump.
  • Suction leaks. When leaks cause the system to suck in too much air, the pump loses its prime and won’t function properly. Common places for leaks include around drain plugs, diverter valves in front of the pump, the pump cover gasket and pump fittings. To address these issues, tighten loose valves, replace leaky fittings and reseal gaskets and connections.

If you do realize you have a leak in your pool, you may be wondering what you should do and how to keep this from happening.

Swimming pool water

What Do I Do If My Pool Pump Is Leaking?

If you see air bubbles in your strainer basket or coming out of the jets in your pool, or if you find water underneath your pool equipment, then you might have a pool pump leak. If these issues aren’t addressed quickly and correctly, you may experience permanent damage to critical components to your pool’s operating systems.

The main way to prevent leaks and keep your pool system in top shape is to consistently perform pool maintenance. For beginners, that can be as simple as adding water to the pool when it’s low, using a net and brush to clean the pool and regularly emptying debris from the skimmer, pump strainer and impeller. However, there are tasks that are best left to a professional, such as performing routine diagnostic tests.

Unfortunately, no matter how clean your pool is, other problems can lead to leaks. For example, your pool pump cover gasket is a common culprit for leaks. These gaskets wear out over time and need to be replaced periodically. Between replacements, you can lubricate these parts with a silicone-based lube to help prevent cracks. The seal between the pump housing and motor and the diffuser O-ring also need to be replaced periodically.

Additionally, leaks can be caused by plumbing connections, pipes and valves that break down over time or crack after exposure to extreme weather conditions. In more complicated cases, the pump itself could be cracked, or there might be a problem with your underground plumbing.

While most pool owners can address basic leak issues on their own, it can be time-consuming to figure out what’s wrong. In the meantime, these issues can develop into even more costly problems. The best way to find the source of a leak and fix it before it causes more problems is to contact a swimming pool expert.

ABC Can Resolve Your Pool Pump Problems

Although pools are meant to be relaxing, problems can develop that can be difficult to troubleshoot, particularly when it comes to pool pumps. Whether you think your pool pump is malfunctioning or you’re having another problem with your pool, you can rely on the certified pool and spa professionals at ABC Home & Commercial Services. Our experienced technicians will be able to quickly determine what is going wrong and get to work on fixing it, so you can get back to swimming.

Learn More