Water pumps and tanks
Curing frequent cycling of a well pump in a private water system, a pump (usually a piston, jet, or submersible type lifts water from a well into a pressurized storage tank.
A cushion of compressed air at the top of the tank keeps the water within a preset pressure range, usually between 20 and 40 pounds per square inch (p.s.i.), When you open a faucet, the cushion of air forces water into the house plumbing system. As the tank empties, pressure drops. At the low limit of the pressure range, a pressure switch activates the pump. Pressure rises as the tank refills. At the high pressure limit, the pump shuts off.
If the pump starts and stops frequently, the tank may be waterlogged-all or part of the air cushion has been absorbed by tank water. Before correcting the tank, look for an open or leaky house faucet. Check and adjust the pressure-switch settings; the difference between High and Low should be 20 pounds. Test for air leaks by applying soapy water to the tank’s upper surface. If bubbles form, tighten a loose fitting, or have the tank repaired or replaced as needed.
To recharge a waterlogged tank, turn off power to the pump. Connect a hose to the drain valve to direct water outdoors or into a floor drain. Open the valve and drain the tank. When the pressure gauge reads zero, remove the air-volume control to let in air (if there isn’t a control, remove a plug at the tank’s top or open an upstairs faucet). Check the control for stuck parts or a leaky float ball; replace it if necessary. Shut the drain valve, reinstall the air-volume control or the plug; turn on the pump.
To eliminate waterlogging and reduce pump wear, consider installing a tank with a precharged, permanently sealed air cushion.