Pump is not a submersible type, and is located near the well. Everything else is located some distance away, with switch mounted just before the pressure vessel; Everything except the switch and pump was just replaced. I know about effects caused by water inertia in case of incorrect location of components, and that is not a problem. Most probably the switch you are using for 20 years was not made in china. Those that pretend to be made in Europe cost much more, and are not easy to find. Sorry, this is becoming quite bit off topic. The main idea is - I do not like that mechanical switch, and was dreaming about digitally controlled substitute for quite some time. Component sellers usually do not mention in their catalogs what medium their sensors are meant for, and it's quite a task to search all those datasheets. Usually those sensors cost quite a lot, but I do not need that high precision, since most probably any of them will be give more repeatable results than the mechanical switch. On Wed, Jun 13, 2012 at 9:36 PM, John Ferrell wro= te: > Some where in the system there should be a pressure tank. The pressure > switch should be as close as possible to the tank. If there is a filter > in the system, it should be as close to the tank input as possible. The > wells around here are deep enough to require submersible pumps. The > pressure tanks have a diaphragm and an airspace. They sometimes need > replacement. The pressure switches last a very long time. I have lived > here for nearly 20 years and not needed a replacement. > --=20 KPL --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .