Submerged well pump, control box?

[stevedore]

My 150 feet submerged well pump correctly cycles on/off (30/50 psi pump switch) about half the time. The other half, it simply does not kick in at 30 psi resulting in no water and pressure dropping to 0. As soon as I reset the breaker for the pump the pump starts again and correctly pressurizes the tank (50 psi) then correctly turns off. The tank, switch and pump are about 25 years old, so I started by replacing the inexpensive parts, the pressure tank and pressure switch. The new tank is properly pressurized (28 psi). But the problem persists ... pump frequently does not activate at required low psi and we run out of water and have to flip the breaker to get the pump to start again. I heard that my problem might be the control box which is also 25 years old. I'm not sure how to diagnose that, but thought I'd reach out here and see if anyone has thoughts that might assist. Appreciate any suggestions!
- Steve

 

[Valveman]

25 years is 4 times the average life of a pump system. It is apparently a lightly used system to have lasted that long cycling on and off like that. Cycling on and off is what destroys most pumps. A heavy used system with irrigation or other large demand would have lasted less than the 7 year average.

The pump will cycle on and off several times, then trips the overload in the motor. The overload cools down in a minute or so and the pump comes back on, but not before the pressure bottoms out and you are out of water for a short time.

Replacing the control box may help as the starting capacitor is also damaged from all the cycling. But most likely you will need a new motor as that one will be full of black crud and the thrust bearing will be low.

Using a Cycle Stop Valve to stop the cycling not only makes pumps last several times longer than normal, but delivers strong constant pressure to the house instead of 30 to 50 varying pressure all the time.

 

[stevedore]

25 years is 4 times the average life of a pump system. It is apparently a lightly used system to have lasted that long cycling on and off like that. Cycling on and off is what destroys most pumps. A heavy used system with irrigation or other large demand would have lasted less than the 7 year average.

The pump will cycle on and off several times, then trips the overload in the motor. The overload cools down in a minute or so and the pump comes back on, but not before the pressure bottoms out and you are out of water for a short time.

Replacing the control box may help as the starting capacitor is also damaged from all the cycling. But most likely you will need a new motor as that one will be full of black crud and the thrust bearing will be low.

Using a Cycle Stop Valve to stop the cycling not only makes pumps last several times longer than normal, but delivers strong constant pressure to the house instead of 30 to 50 varying pressure all the time.

View attachment 47632

Thanks. So perhaps the well pump needs replaced and maybe a CSV will mitigate premature wear on the pump, but hopefully there's an interim diagnostic I can do on the control box and other parts of the system before going through the expense and hassle of a complete pump replacement which, at this point, I'm not sure is even partly or entirely the problem (??).

 

[Valveman]

I always replace the control box before pulling a pump. But with a new control box if it still fails to start at 30 occasionally, it is a motor problem. Just from the age and the fact the pump has been cycling for that long I can tell you what it looks like inside the motor, and it is not pretty.