How does a swimming pool pump work?

A swimming pool pump has a simple function: to circulate the water in the pool’s hydraulic network to pass it through the filter, thereby treating it.

Naturally, if it is the pump that sucks up and propels the water, it is extremely important that the hydraulic network must be designed correctly, in particular to avoid load losses and to pass as much water as possible through the filter. If this is the case, and you have chosen the pump that is suitable for your pool, it will then be able to provide you with the ideal flow rate for minimal energy expenditure.

General swimming pool pump operation

The core of a pump consists of a motor connected to a turbine: when turning, this sucks water from the pool skimmers.

The water then enters through the front of the pump and firstly passes through a prefilter that captures residual debris and retains a useful reserve of water for priming the pump.

While being sucked in, the water then enters the turbine, which pushes it towards the pump outlet. The water is now propelled: through the filter, then through any treatment devices and/or the heat pump, and finally to the nozzles that discharge the water into the pool. The cycle then starts again from the skimmers.

The mechanical seal: an essential element for the lifespan of your pump

A particularly important part of the pump is the mechanical seal, which ensures watertightness between the pump body (fixed) and the motor shaft (rotating).

It is important that this mechanical seal - a rotating seal - is in water when the pump is started: otherwise, the seal may overheat and destroy itself in a few minutes.

If your pump is below the level of your pool, don't worry, as it will always be loaded with water (naturally, if the water in the pool reaches the level of the skimmers and passes through the pipes, be careful about evaporation).

However, if the pump is above your pool level, opt for a self-priming pump. This variant can suck up water even in the presence of air, thanks to its diffuser (yellow part in the diagram), which prevents the flow of pressure from returning to the front of the turbine, resulting in a considerable loss of efficiency.

The rotating seal is a part that wears out logically with time and friction. Remember to replace it to preserve the motor and your pump's lifespan: replace it as soon as you see a leak. Don't panic, this is an inexpensive operation (the price of the seal) and accessible to anyone with a basic knowledge of DIY.

More important than the pump: the hydraulic network design

While the pump is naturally one of the main devices in the pool, it is still worth remembering that the most important thing is the design of its hydraulic network. To sufficiently filter the water every day, a certain flow rate is required. To ensure this flow, large pipes are especially useful, installed in order to avoid load losses between the skimmers and the pump (suction part). Remember that once the hydraulic network is buried, it is no longer accessible. Hence the importance of designing it well from the outset.

Only when you feel assured that this network is well-designed, will you be able to choose a pump with a calm mind.