Pressostats can fail but they don't fail very often. I would look at other things before messing around with it. Hose restrictions, inline filters, low water pressure, kinks etc can all result in the kind of symptoms you describe. It could also be a faulty aquastop...or even a PCB fault if you are very unlucky. Check the easy things first & remember the golden rule...it it ain't broke don't fix it.
Mike, October 2009
