When a system is fully primed, the system components, pipes, pump, filter etc., are filled with water and the pool pump is able to suck water from the pool and push it back into the pool through pool returns. Priming a pool pump involves purging air from the pumping system and filling the water lines and pump with water. The number of steps required to prime your pool pump depends on the amount on water in the suction side of the lines - water coming from the pool to the pump. If you are installing a new pool system, there is no water in the lines, and you may have to repeat these steps several times. If you are adding or replacing components into the pumping system (like a heater), there will still be some water in the lines and priming will be simpler. The following procedure assumes that you have no or little water in the system. Visible indications of low water are no or little water in the pump strainer box, and a low pressure reading on the pool filter pressure gage.
The suction diverter valve allows you to shut off water from the skimmers or from the main drain. Generally you cannot shut off both. To prime the system in steps, move the diverter valve so that the off side of the lever is pointing to the main drain side. Now water can only flow from the pool skimmer lines. Note: if you are only adding a component to an existing system, water will still be in the lines and you can probably re-prime the system by opening the skimmer and main drain lines at the same time (lever is halfway between skimmers and main drains).
Next you will have to relieve any pressure that remains in the pool pump and water lines. To relieve pressure turn the air relief valve on top of the pool filter counter clockwise. You will hear air releasing as you see the pressure on the pressure gauge go to 0 psi. Leave this relief valve open.
Open the lid to the pool pump strainer box. To open up the strainer box, 1-turn the two knobs on top of the strainer lid counter-clockwise and 2- swivel the knobs down away from the lid. Note: Some strainer lids screw on instead of having knobs. In these cases twist the lid counter-clockwise to remove the lid off the top of the strainer box.
Ensure that the diverter valve to the pool return is open. This will allow the pool pump to discharge water to the pool. If this is not open, excessive water pressure that builds up during pump operation may damage parts of the pumping system and may be dangerous.
Check the water flow through the strainer box. Water should flow freely in 30-60 seconds.
If water isn't flowing freely in 30-60 seconds, repeat steps 1 - 10: turn off the pump, bleed off the pressure, reopen the strainer, refill the strainer, and close the lid. Then turn on the pump. You may have to repeat these steps several times to purge the air from the line.
When water is flowing through the pool skimmer lines, slowly open the main drain line at the diverter valve. Open the relief valve to allow air in the main drain line to escape. Again water should flow freely in 30-60 seconds. Close the relief valve. If you don't see pressure building on the pressure gauge and a full strainer box, repeat steps 1 -10.
If, after repeated attempts, you cannot prime the system successfully, your system has a major leak or blockage. This problem must be resolved before you can prime the swimming pool system.