Pump continues to run replaced pressure switch didn't help check pressure coming from pump could only get 20lbs which seems extremely low also check pressure going to switch it was also 20lbs does this tell me that the pump is worn out, are what.please help need water the pump is a water ace 1/2 hp 3450 rpm thanks mike

Does the pump hold pressure when it's not running ? Is 20 PSI the best it will do?
Let me know, Tom

Could be a restricted intake piping. Foot valve or check valve would be a good place to start checking.

Have you thought of checking the air pressure in your water tank?
Most wells have a storage tank to not only hold water but air pressure as well. With the pump turned off at the breaker box drain the water out of the system and take an air gauge and check the air pressure in the tank the same as you would a car tire.

The air pressure in the bladder tank needs to be set too 2 pounds below the cut on pressure of the pressure switch.
Ex: 30 lbs. cut on pressure = 28 lbs. air pressure in the bladder tank.

Now before you drain the water from the system with the power still on Push on the valve core to let a little air out of the tank. If you get water mixed with the air you will need a new bladder tank.

I wish you well,

Van

Van, good idea to check pressure tank. However, tank will not cause pressure to only build to 20psi. If tank were bad, and pump were working correctly with no flow problems, that pump would just build pressure more quickly then turn off then back on again. You could actually remove the tank and the pump would(if working correctly) still build a pressure determined by your pressure switch. Like I said, its great info you gave to check pressure tank,, always a good idea, but I really don't think this is the root of the problem.

PS. To others out there reading this,, never remove your pressure tank, I was only giving a hypothetical. Pressure tank is a very important part of your pump system.