Hello all. I recently had the expansion tank and pressure switch changed in our home by a reputable company.We have a submersable pump and seem to have plenty of water. The reason was that when the pressure got to 30 lbs,the "cut in", it would fall below 30lbs. and not "cut in". The Plumber told us that this would fix the problem. It did for a day or two. It is doing the same old thing. When pressure gets to 30lbs it quickly falls and won't return to proper pressure and I have to manually turn the switch back on, usually when I am in the shower. I am sure that I have not provided enough details so let me know what you need. Thanks!!