The parts of a residential well water system include the pump, pressure switch, pressure tank and distribution system. When these parts work together, water flows from the well to the taps inside the home.
Many drilled water wells use submersible pumps. These units are approximately 3 1/2 inches in diameter and fit inside the well casing below the water level. The ground provides frost protection for these pumps, but well repair personnel must pull them up if they require repair. Jet pumps are installed at ground level, but generally provide lower pressure and volume than submersible pumps. Jet pumps also require frost protection.
The pressure switch activates the pump to maintain the water pressure in the tank between the set points. The switch turns on the power for the pump when the home uses enough water so that the pressure is at a lower point and powers off the pump when the pressure reaches its maximum set level.
As water pumps into the pressure tank, it compresses air to move the water back through the distribution system. The tank reduces wear on the pump by preventing it from switching on and off constantly.
The distribution system is a set of pipes that carry the water from the pressure tank to the fixtures in the house. This system feeds a water heater so that the home has both hot and cold water.