My Galvanized Well Water Tank Is Losing Pressure

What Pressure Tanks Do

• Well pressure tanks are designed to maintain steady water pressure in a rural water system. They reduce the demands on the well pump itself, prolonging the life of the most vital part of the system. A secondary function of the well pressure tank is to eliminate variability in water pressure at the faucet; constant pressure on the water system makes water flow much more smoothly.

Bladderless Tanks

• Galvanized tanks are the oldest style of pressure tank still in use. They began to lose popularity after the 1970s, when the bladder tank came on the market. Bladder tanks work by physically separating the water in the tank from the air. Well water in bladderless galvanized tanks dissolves some of the oxygen, eventually leading to a drop in pressure.

Air Volume Control Valves

• Bladderless galvanized well tanks should be equipped with an air volume control valve. Several designs exist, but the purpose of each is to bleed excess water from the tank and maintain as much air pressure as possible. These valves can fail, resulting in a loss in pressure. If the valve itself isn't defective, failure could be due to an obstruction in one or more of the valve's openings or a pump-control valve with improper settings.

Repressurizing

• As long as your well pressure tank is not leaking, repressurizing the tank is easy. Turn off the well pump before opening a valve at the bottom of the tank, allowing water to drain out. Immediately open the valve on the side to allow air to flow into the tank. Once the water has finished draining, close both valves and use an air compressor to repressurize the tank through the tank's Schrader valve. The pressure inside the tank should be about 15 psi less than the pressure setting on the well. Turn the pump back on once you are happy with the pressure reading.