When an above-ground pool is unable to pump the water through it with force, its pump needs to be primed. This process pushes out any blockage within the system to restore efficient water flow.
The main source of obstruction is usually air bubbles. When a pump is primed, the air is purged so water can flow through. Follow these steps to prime an above-ground pool pump. It may be necessary to repeat them a few times, but stick with it. Without this process, the quality of your pool water will suffer.
Step 1 - Get the Pool Pump Ready
If the pump is running, switch it off. Unplug the electrical cord or turn off the circuit breaker so the power to the pump is disconnected.
Step 2 - Close the Valves
There are some valves on the suction of the pump, which are the main drain, skimmer and vacuum lines. Close all these valves. Locate the air relief valve on your filter, and open it to release any pressure that has built up inside the pump. Very slowly, open the strainer lid of the pump. If your above-ground pool pump does not have an air relief valve, use the strainer lid to release the pressure. Again, use caution! The built up pressure can be dangerous.
Step 3 - Inspect and Clean the Strainer Basket
The strainer basket of the pump sometimes gets clogged with debris like leaves and sticks. Remove everything carefully and return the basket to its place. The basket might be broken or distorted. If so, the impeller of the pump may have some debris on it as well. Clean the impeller, and put in a new basket if the old one is damaged, as it may be harmful for the pump. The strainer top is sealed with a gasket or "O"-ring, which you should also check for cleanliness. If it's bent out of shape, replace it.
Step 4 - Fill the Strainer
Use your garden hose to run water into the strainer. Then, put the strainer lid back on and push it down well, twisting it into place securely with your hands only. If there are knobs, use both your hands to tighten them firmly and evenly. Try to avoid using a wrench. If you over-tighten, the knobs might break.
Step 5 - Run Water Through the Pump
Switch on the pump, then open one suction side valve very slowly. Within a minute, the pump should be able to catch its prime and get the water flowing through it. If it doesn't catch within a minute, shut the valve and switch off the pump. Allow the water to flow by reopening the strainer valve.
Release the pressure by opening the air relief valve on the filter. Repeat the entire procedure by refilling the strainer with water, closing the lid, turning on the pump and opening the same valve. These steps may have to be repeated several times before you purge all the air so the water can pass freely through the pump.
Step 6 - Add All the Lines
Slowly open the other valves, one after the other. With every line, the same procedure has to be followed to remove the air from the line without losing the prime.
If your above-ground pool pump keeps losing the prime when you turn it off, try to release the air in the filter first before you turn off the pump. You should always close your suction side valves and then proceed to open the strainer lid. The water is then held right up to the valve, which should make it easy to re-prime.