water pump problem

[Jamey]

My water pump only works if I hook the city water up to the outside connection and then I can hear the pump prime. I can disconnect the city water and the pump will work from the tank water fine for a few days then stops until I hook the city water back up. I cant understand why its doing that. Anyone ever have this???

[John Perry]

My water pump only works if I hook the city water up to the outside connection and then I can hear the pump prime. I can disconnect the city water and the pump will work from the tank water fine for a few days then stops until I hook the city water back up. I cant understand why its doing that. Anyone ever have this???

It sounds like the pump may be sucking air through the city water connection and losing its prime.
Hope this helps,
John

[Gerry]

My water pump only works if I hook the city water up to the outside connection and then I can hear the pump prime. I can disconnect the city water and the pump will work from the tank water fine for a few days then stops until I hook the city water back up. I cant understand why its doing that. Anyone ever have this???

I think John has it backwards... the city water is keeping you pump primed...
When you disconnect from city water what is happening is your loosing your prime.
You have a small air leak on the suction side of the pump.
If you let this system sit long enough for this small air leak to form a bubble large enough to get into the pump and it will loose its prime and not be able to pump.
1) make sure suction line is submurged in the water tank to be sure your not sucking wind.
2) if this is OK... plug this end off, of intake line and put city pressure on system to see if there are any other leaks in suction lines or on pump, if so fix them and solve your problem. Leaks on outward bound water will not matter unless an air bubble can get to the pump.
Gerry

[BobB]

I'll vote for replacing the pump. How old is it? What brand? What model? Some models aren't harmed by running dry and will pump air as well as water. They do not need to be primed. This can also be helpful when you are winterizing!

[Jamey]

My pump is a flojet and I am not sure how old it is. I know for sure the pump works fine because when I bypass the pressure switch at the top of the pump it works. It actually blows the outside connection off when I bypass the limit switch. My guess is that the problem is in the limit switch or regulator. It would be nice if I could just purchase the top piece. If I had other leaks it most likely show up when I hook the city water up. Thanks for all your help.

[Donna D.]

Well, this is in the Document Center and it's for a Shur Flo, but it's for troubleshooting...maybe it will help

Shurflo Water Pump Troubleshooting

[Frederick L. Simson]

I know for sure the pump works fine because when I bypass the pressure switch at the top of the pump it works. [b]It actually blows the outside connection off when I bypass the limit switch.

How does the ball valve seat in the "City Water" fitting? Is it still there?

[John Perry]

I think John has it backwards... the city water is keeping you pump primed...
Gerry

Gerry,
Why does his pump work well for a few days after the city water is disconnected?
John

[Gerry]

Gerry,
Why does his pump work well for a few days after the city water is disconnected?
John

John, Jamey doesn't say he uses the pump during those few days after he disconnected and I assume he is not.
This give time for the faulty check letting water back to holding tank and the leak on the suction line to let the air in line.
The age of the pump and faulty check systems in the pump or extra parts may be such as the pump can not pick the water back up.
Jamey, you may want to just buy 2 small check valve before purchasing a new pump and install on the suction line and the city water line.
Gerry

[BobB]

Troubleshooting Flojet water pump (failure to prime). You may be able to find a repair kit if that is what you want to do:

Debris in pump--Remove upper housing and clean out

Defective check valve assembly--Replace check valve assembly

Air leak in intake line--Inspect plumbing and tighten clamps

Punctured diaphragm (pump leaks)--replace lower housing or pump head

Crack in pump(pump leaks)--Replace housing or pump head

[Pete Dumbleton]

Frederick has nailed the first thing wrong with your system -- Check valve(s).

Because of the check valve in the city water connection, and the check valve in the pump system, when the city water line is pressurized, the pump check valve should be seated and nothing should go through the pump (nothing backwards and it shouldn't turn on), plus the line between the pump and tank should stay primed. Since it doesn't seem to keep its prime, the pump check valve is likely defective.

If you open the unconnected city water spigot, manually start your pump and water flows out the spigot, your city water check valve is defective.

From personal experience, I can attest that if one pushes on the central pin of the city valve, from outside, one risks misalignment of this valve and it is VERY tedious to get back in proper alignment so as to seat properly... It's easy enough to replace the whole thing and have new spring, seal and seat.

[Jamey]

Finally fixed the problem. I didnt know but the top little black box or pressure switch at the top unscrews from the top of the pump. I took it off and took the switch apart. The contacts were real dirty and it wasnt even making a clicking noise as the switch should. Cleaned the contacts and now it works fine. Dont know how it relates to city water hook up but I know that it was the problem.