Well pump only runs when I hold switch manually

I just had a new red jacket pump installed and it has a centripro AS4CB pressure switch on it. I lost power and now pump wont start. I read posts here and other places that say there should be a reset switch thingy on the side, like a little lever that you hold up until there is enough pressure, then it works on its own. Mine does not seem to have that. I took the lid off the pressure control box and found it has power going to some magnet things. Then there is a black piece of plastic that has metal on it. Looks like the magents are supposed to suck the plastic/metal towards it. When I push the plastic to the magents, the pump kicks in and I get water. Just cant get it to kick in once I use up the water in holding tank. Not sure why this would happen. I thought plumber did a good job and its been working (3 days seemed fine). Is there some other type of reset switch? Also, I do not have a pressure guage on the pump.

Most likely it's a sensor problem. Computerized pumps are a night mare. Simplest solution is convert to a conventional pump and install a Pside-Kick http://www.cyclestopvalves.com/products.html.

if its only been 3 days, i'd call them.. unless he didnt supply the parts in which case he might not have to honor any warranty.

Just a quick thank you. Works now, needed to get a heater blowing right on pressure switch, works fine now.

The magnetic thingie would likely be a magnetic contactor or motor starter. If the pressure switch is froze up, it will not get a signal to close.

You probably have a pump control box, which takes the heavy starting load off of the pressure switch. Its a very good system.