How To Prime A Swimming Pool Pump

Proper operation of a pool pump is essential to keep the pool water safe and clean. The pump is said to “lose prime” when too much air enters the pool lines. Priming a pool pump is the process of releasing trapped air in the system to get the water to circulate properly. This way, you can start splashing in a clean pool in no time.

Prime the pump at the beginning of each pool season. Although the pool has been covered during the off-season, the water in the pump and lines may have evaporated or emptied. When you prime the pump, add water to it and drain the air in the lines.

Equipment you will need

Petroleum jelly (or a similar lubricant)
Garden Hose or Bucket

Turn off the pump. The pump must have a kill switch somewhere. Flip the switch to turn it off. If it doesn’t turn off, find the wire that goes to the wall. On the wall, there should be a circuit breaker that you can flip to turn off the electricity to the pump. That way, you won’t be working on an electrical item while current is flowing into it!

Remove the cap from the pump. The pump is covered with a lid to create a closed system. You will likely need to unscrew the cap to get to the pump. The cover must fit snugly so that it does not allow air to enter the system when it is operating.

Turn the multi-port valve to “recirculate”. The multi-port valve should go in the pipes next to the pump. If you’re not sure what it is, look in your owner’s manual for your particular pump. Turn it to the place marked “recirculate.” This allows the water to flow only into the pump and not through the filter.

Release the air pressure in the filter by turning the air valve. Find the valve on the top of the pool filter. It is a small round goatee. Turn it to the left (counterclockwise) to open the valve. The gauge should read 0 psi when you’re done. Leave the valve open.

Look for the debris in the basket on the pump box. The pump basket should be just below the cover. If there’s anything in it, take out the bomb and get rid of it. Rinse the basket with a hose if you need to.
Put the basket back in the pump.

Pour water into the pump box and pipes. Use a hose to fill the pump with water. You should see how it fills to the top of the pump basket. Fill the area for at least 2 minutes so you know the water has reached the pipes. If it drains, add more water.

Put the cap back on the pump. Make sure the cover is tight before continuing to the next step. The suction could knock down the cover when you turn the pump again if the cover is not tight. You need to screw the cover back into place. This is a good time to check the cap and seal for cracks. If it’s damaged, you’ll need to replace it.

Turn the pump back on. You will have to flip any circuits that you have turned off again, including the one in the wall of the pump. With the pump back together, you are in less danger of working with it near water.

Look at the water pump and the air valve. You should see the water running through the pump pretty fast. The water pump may gurgle with air bubbles at first, but it will soon start running smoothly with just water. You can also see the air valve. If there are air leaks, start spraying a little water to get the pump to work properly. If you don’t see these signs within a minute or so, turn the pump off again and repeat the steps above.

Close the air valve and turn the multi-port valve to “filter” again. Once the pump is running smoothly, turn the air valve clockwise until it is tight. That will close the valve and the pump system. Also, turn the valve so that the water returns from “recirculating” to “filtering”. In this step, the water must flow back through the filter.


Add more water to the pump and skimmer lines if it doesn’t work. Generally, if the pump has a problem, it is because it cannot get enough water through the pump. Turn off the system again and fill the pump with more water, then treat again. Make sure to always turn off the pump before removing the cap to add water!

Check the pool water level to see if there is enough water for the pump. If the pump has nothing to draw water from, it cannot work. If the pool level is low, try to fill it to normal levels before working on the pump again.

Tighten all the valves to ensure a good enough seal for the pump to run. Turn off the pump. Tighten the air valve and the water valves. Also, tighten any accessories. You may need to use a wrench to tighten the pump parts. Turn it on again to see if it helped.

Wash and lubricate the cap to determine if this is why the pump is not working. One issue that can cause pump problems is that the seal is not tight enough with the pump cover. Turn off the pump and remove the cap. Rub the cap and threads with dish soap and water and rinse well. Dry the cap and rub a lubricant on the o-ring under the cap. You can use petroleum jelly for this purpose. Put the lid back on tight. The purpose of this is to tighten the seal as much as you can. Turn the pump on again and see if it works.

Look for leaks in the tubing leading to the pump to see if there are any problems. Grab a can of shaving cream and add a layer all over the pipe leading to the pump. Turn on the pump and look at the cream. If it flows into the pipe, there is a leak. You may need to replace the tubing or have someone do it for you.

Call an expert if you can’t find the problem. The repair may be something only a professional can find and fix. This is true if the problem has to do with the motor or the wiring.

Procedures for priming a pool pump may vary slightly from system to system. Follow the manufacturer’s instructions for a specific filter system or contact your pool supply or maintenance provider for assistance.

Don’t run a pool pump without water whenever possible. Doing so for significant periods of time can cause serious damage to the pump, motor, or both.