One common problem with hydro pneumatic tanks is loss of air cushion, resulting in a “water-logged” tank. Source: iStock
With the increasing popularity of the submersible pump in the 1950s, this became a serious problem. Most of the time the owner could not hear the pump run, was not aware of an impending problem and only called for service after the pump had burned out its controls or its motor. On a rare occasion, perhaps one time in 25, where a serviceman encountered a water-logged tank he would encounter an air-logged tank. This was a tank full of compressed air. Opening a faucet connected to one of these usually resulted in a broken drinking water glass, upsetting the owner greatly and sending his wife into orbit. However, as I just said, in our area this was a more rare condition.