This started a few months ago. When we flush the toilet or run the water a few minutes later a noise (that sounds like the washer spinning) comes from the points that shut the water off from the well. It's like a bump, bump, bump, bump, bump then it stops. This happens several times per day. We have one of those blue tanks and it has air in it. The noise is coming from the points, I shut the power off and took sand paper to them and this didn't help. Any information about what this could be from would be very helpful as we are trying to sell our house.