The standard equipment associated with circulating the water in a swimming pool are the pump and motor, filter, heater, and surface skimmer. The water circulation system is a closed system. The pump, which is driven by the motor, is normally located on the intake side of the filter. It draws water from the pool and forces it through the filter where dirt particles are removed. The water then flows to the heater and then back to the pool. To prevent the pump from getting clogged, there is a strainer basket on the water inlet side of the pump, which catches hair, lint, and other debris.
There are three basic types of filters available for swimming pools: sand filters, cartridge filters, and diatomaceous earth (DE) filters. The filters have no moving parts, and any one of the three will provide effective filtration. No matter which filter is used, the filtering medium will require periodic cleaning. The process used to clean DE and sand fil-ters is backwashing, which is sending water backward through the filter, thereby flushing the debris onto the lawn, into the street, or to an approved drain line or sewer. Cartridge filters are not cleaned by backwashing; the cartridge is simply removed from the casing and washed. Most filters have a pressure gauge that is mounted on the top of the casing. The normal operating pressure is usually around 10 to 12 psi, although for some of the newer filters, it may be between 5 and 7 psi. As the filtering medium becomes dirty and clogged, it takes more pressure for the water to flow. It is generally time to clean the filter when the filter pressure increases approximately 10 psi above the normal operating range.
A swimming pool heater is not mandatory, but most houses with pools have one for comfort and because the heater can extend the swimming season. Most swimming pools are heated with a gas-fired heater, although they can also be heated with an electric heater and to a limited extent with solar heating or a heat pump. The ignition system in gas-fired heaters will be either a pilot light or electronic spark ignition. Either natural gas or propane gas (LP) can be used as the fuel for firing the heater. However, a heater that is designed for natural gas should not be used with propane gas and vice versa, because it will not operate properly. Keeping the pool water in the proper chemical balance is very important not only for health reasons and maintaining the quality of the water but also to extend the life of the pool heater. Water that is out of balance will result in a scale buildup within the heater, which if not corrected will cause a blockage of water circulation.
Most swimming pool shells have at least one to two built-in surface skimmers with skimmer baskets that are tied into the water’s circulation system. When the pump is operating, dirt, leaves, oils from lotions, algae, and other debris that float on the water’s surface are drawn into the skimmer by floating over the entrance weir. (See FIG. 18-5.) The baskets trap and collect the larger debris, and the oils and dirt particles circulate back to the filter where they are removed from the water. Some pools have skimmers that are also connected to a pipe located below the water level. This pipe prevents air from being sucked into the circulation system when the water level is down. Otherwise, when the pool water level is below the bottom of the weir, air will be drawn into the circulation system, which could damage the pump. The pump is not designed to run dry. Running a pump with air in the system or running it dry can cause overheating and seriously damage both the pump and the motor.
There are a number of accessories associated with a swimming pool, but the ones of concern from an inspection point of view are the pool cover, diving board, ladder, slide, and grab rails.
The main use for a pool cover is to keep debris out of the pool. It is mostly used when the pool will not be used for an extended period of time, such as during the winter months. (See FIG. 18-6.) However, depending on the material and design, the covers are also used by some homeowners during the swimming season to minimize heat loss and maximize heat gain. There are also safety covers that prevent small children or animals from falling into the pool. These covers are reinforced mesh with spring-loaded straps that hook onto the deck. There is also a “thermal or solar” cover available for a pool. It is essentially a sheet of vinyl bubble wrap that floats on the water. One puts it over the pool during swimming season because it allows the sun to heat the water and because it provides a barrier against evaporation.
Diving boards are available in spring-assisted and simple platform models. They are covered with fiberglass to make them waterproof and topped with a nonslip coating. Because of the danger of injury, some homes have jump boards rather than diving boards. Jump boards are shorter and are considered safer than diving boards. The concern about ladders, slides, and grab rails is whether they are adequately anchored to the deck.