What could cause air to get into your water lines in your well water system?

Air in water lines

It's possible that your jet pump could be sucking air from your holding tank. There is usually a float switch from your well to the holding tank depending on the system. The float switch determines how much water is pumped into the holding tank. if the holding tank isn't full enough your jet pump could create a vortex in the tank causing it to suck air. It could also be the case if your jet pump is oversized. It could be a serious problem depending on how much air is being sucked through the pump.