I had a new 4 inch well installed last spring and the well is 80 feet deep. The installer used a one half hp submersible pump.

Next to the well casing is a four or five inch PVC casing, sticking out of the ground a foot or so, with a cap. Under the cap there is a homemade type lever that can be turned counterclock wise. I'm told that by turning the lever one quarter turn, it will open a valve and it will drain the line from the supply pipe to the expansion tank back into the well to keep it from freezing, when not using the well duirng the winter.

Is this correct?

Thanks.