I've got a submersible well pump working into a WellMate 40 gallon tank. It's a non-diaphragm type - Model no. SP-9. Cut in pressure is 40 PSI; shut-off is 60 PSI. There's an air volume control on the side, about 15 inches from the floor. (Pic attached) The tank is about five years old; the pump three years old with new piping up to the wellhead.
The issue is that I'm getting air bursting from cold water outlets whenever there has been significant water draw, such as a lawn hose or the softener regenerating. The warm water, which is all softened and - of course - heated doesn't display a lot of this, but there is some air there also. This doesn't occur with normal day-to-day use, just when I'm drawing water outside the house, or after the softener has regenerated.
I figure that I've got either (or both) of two situations:
1. My pump is outrunning the water source under high draw, and It's pushing air up the line with the water.
2. The air volume control isn't venting reliably when the tank level is low. (I believe this is a float actuated valve, apparently with an orifice to limit its output.)
My immediate question is whether the operation of the air volume control is adjustable - there appears to be a slot on the plug in the body of it for a screwdriver - and whether this is relevant.
Anybody have experience with this?