Pump runs all the time...sometimes

I'm working with an old system like this at a friends house :
http://www.inspect-ny.com/water/JetPumpPressureSw010DJF.jpg

All was fine until the pump began to run continuesly, The switch was replaced and we pulled the steel plug out of the motor itself and cleaned it out. Pressure throughout is fine. However, even with the new switch the pump runs all the time, sometimes. If you run water for 3-10 seconds and turn it off, the pump comes on and turns off properly. If you flush the toilet, or leave the sink open for 30 seconds or better the pump locks on and will not shut off unless you force the switch off, then it turns off and stays off, and goes back to working properly for the 3-10 second usage.

My theory is that tiny copper line is getting plugged up, so even tho the pressure is there, that line ever tells the switch it is. Is a last ditch effort to cram something through that line a good idea before a new pump is purchased? I don't feel the air tank is the problem, its holding air and pressure in the house is completely normal.

If it gets up to the correct pressure and does not shut off, then you are right that the pressure switch is not seeing the pressure. If it doesn't build enough pressure to shut off, it is a pump or well problem.

Replaced the pressure gauge and of course, the old one was junk, the system will only build 30psi. Seems the damage is done, the pump is a 15 year old goulds pump, seems it won't see 16.

A pump turning on and off quickly can indicate a bad pressure tank or a problem with the air charge.

If the pressure tank is as old as the pump just replace both at the same time.

The copper is usually 1/4" and it uses compression nuts and a ferrule or they'll use flared fittings. Either way, clean it out and the fittings and where they go into the pump and the switch.

If it doesn't work well then, you may have a partially blocked jet or less water in the well than before.

Kurt

valveman said:

If it gets up to the correct pressure and does not shut off, then you are right that the pressure switch is not seeing the pressure. If it doesn't build enough pressure to shut off, it is a pump or well problem.

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How do I post a question and get an answer?

I am starting a well pump for the first time.
The well was shut off back in October 2007.
I had to install a new tank, after that I turned the power on, ran water thruogh the garden hose for about 30 minutes.
I turned off the hose and niticed that the pump was still running.
I closed the valve suppling the house and the pump does not seem to build more than 40 psi. When I turn the pump off the pressure drops to zero witnin 2-3 seconds, almost Like ther is a leak.
Could the supply line running to the house be cracked or is ther another problem ?

If everything is tight on the suction side and you are only getting 30 lbs it could be a couple things. The foot valve may not be opening all the way, very rare but possible. Usually they don't close and cause a different issue. More likely though is the jet has something partially plugging it or the impeller is plugged or worn out or there is a hole in the diaghpragm.

Yes a leak anywhere from the pump (assuming a submersible, you don't say what type pump) to the pressure tank will cause that. Especially if it is above the water level in the well.