How Do Swimming Pool Pumps Work?
The beautifully inviting blue water in a well maintained swimming pool did not get that way by chance. A system of filters keeps the water clean. A simple impeller pump moves water through the filters and back out into the pool. This pump is the only moving part most pools have. Its workings are not hard to understand.
The pump that pushes our swimming pool water through its filters are usually hidden away out of sight. Its operation may seem like a mystery to pool users. In reality, the workings of a swimming pool pump are quite simple and very similar to a familiar household appliance.
The washing machine analogy
Picture the agitator of a top loading washing machine. A central shaft attached to a motor is fitted with radial mounted fins. The whole assembly turns and the fin pushes the water in your washer around and around. The agitator functions as an impeller, just like the one in your pool pump.
How a swimming pool impeller works like an agitator
The pump in your swimming pool has a housing, the equivalent of the washer's tub, that encloses its impeller. The housing is tightly sealed, and the fins on its impeller fit closely inside. The impeller has just enough room to turn. When the pump's electric motor spins the impeller, it pushes the water inside the housing around with great efficiency.
The spoon analogy
Imagine that you dip a spoon into a bowl of soup. Holding the spoon level, you lift it straight up, and a spoonful of soup comes with it, because it cannot pass through the metal of the spoon. Now imagine that you tip the spoon. The soup can pass through air just fine, and it plops back down into the bowl.
How a pump works like a spoon
Water will move around inside the pump housing only as long as it has nowhere else to go. Providing an outlet on one side of the housing gives it an escape route, so that the impeller can push water out of the pump. On the other side is an inlet, which draws in water to fill the vacuum left by the water pumped out, usually through a skimmer basket to keep large pieces of debris out of the pump's workings. Since the swimming pool water goes through the filters and back into the pool, the process continues as long as the motor is on.
Swimming pool pumps form a vital part of the filtration system that keeps our pools safe and pleasant to use. These simple devices make it possible to move water out of the pool for treatment and then back in to enjoy. Understanding your pump will help you get it the maintenance it needs to function perfectly for many years.