Hello I had a jet pump that would only build 40 psi originally 50psi. Checked pressure tank with no water in system and it had 0 psi, it wasn't water loged. Filled to the proper 28 psi and tried pump still 40 psi. tank still held pressure for week plus no leak there. Decided to get a new pump thinking impeler blade must be broken. I talked to my neighbor he said he had a good one and brought it to me. I plumbed in and it only biult to 25psi. So I dug in my pocket and bought a new pump. The same only 25 psi. but it doest leak back down. So I pulled the lines from my 3 inch cast iron well(41 feet deep, 28 foot of water) replaced foot valve and elbows on pipes and reinstalled. Still the same 25 psi the injector were the 2 lines come together is under water. I have primed my pump the way the book that came with the pump told me to. And it will build up to 25 psi and that's as far as the pressure will build. I got to thinking that my lines runnig to my well had a hole in them some were but it has held the 25 psi for over a weak now, and when I drained the system the lines still have water in them. And it will build right back to 25 psi with out having to prime again. If any one can give me any help please let me know thanks.

When it pumps up to 25 PSI does the pump shut off or just keeps pumping without building up pressure?

It keeps pumping and never stops. The switch is new and came already on the new deep well jet pump.

It sounds as if the pressure switch isn't properly calibrated.

If the pressure switch wasn't set correctly it would shut off the pump early. This is not the case. It just continues to run without shutting off. Or this is how I under stand it. If wrong please educate me so I can fix it. Plus the switch came on the pump so I am assuming that it is pre calibrated. I don't know but any info will be helpful, cause I am at my witts end.

You are correct. If the pump is continuing to run, then the switch is doing its job. If the system will hold 25# pressure for several days, then the new foot valve would seem to be doing its job. My only thought would be this. Jet pumps are sensitive to any leaks in the suction side of the well pipe, no matter how small. I know you mentioned you replaced some of the pipe and checked some of the rest (I got to thinking that my lines runnig to my well had a hole in them some were). How old is this pipe and what kind is it? The fact that it originally would only pump up to 40 and then has progressively gotten worse might point in that direction.

That was my next thought as well. But it seems to be holding water in the line. Would that make a difference? But it went from 40 psi to 25 psi in just the time it took to change out the pump no middle ground in between. But it would make sencce if it is sucking air as well as water to not build pressure. Also when it build to 25 psi it is almost instant with no struggle. I don't know I'm just really confused. I just wish there was some sure answer before I go diggiing 40 inches in the ground with a shovel. And I just think it should struggle to get to the 25 if it were sucking air??

Well, I'm running out of ideas. The only thought left is this: What kind of pressure tank are you using? Is it a bladder tank? The fact that you build up to 25 pretty quick is normal for a bladder tank. Also, is there a check valve between the pump and the tank?

Yes it is a bladder tank, air on top, water on bottom. No there is not a check valve between the tank and the pump. So are you thinking that the air in the bladder is causing it to read 25 psi quickly, and that there could still be a hole in the line from the pump to the well? Cause that kind of makes sense to me if you are?

I mentioned the check valve since, if between the tank and pump, it would have isolated the tank from any leak "upstream" of the pump. So much for that idea. I, for one, am grasping at straws at this point.

However, I would check the pump for volume. You probably know how to do this, but just in case, just run water from the nearest spigot to the tank into a five gallon bucket to see how much water you get in one minute. It should be at least five gallons a minute, probably more, and should be able to hold it steady for many minutes. I cannot imagine your pump doing that if it cannot pump over 25# pressure, but it will only take a few minutes to find out. I would think that, if there is air in the water, you will be able to hold the hose under water in the bucket and see any air present.

One way or the other, you can always call the pump manufacturer and check with them. With the pump under warranty, they will have a vested interest in giving good advise.

Let us know how it works out. I wish I could be of more help.

OK I had time to call the manufacture of the new pump and the said that I must use there ejector kit with the twin injector. I told her that I figured an injector was an injector no matter what brand. But she gave me some insite on there kit contains a venturi tube that conects to it. Witch for people not knowing and trying to get some answers by reading this post, a venturi tube is a tube that starts a one diameter on one end then restricts down too a smaller diameter at a spesific angle to create pressure, and in some cases swells back to the original diameter. So I am going to see if I can't find this kit and install it. Then I will post back to tell my results. Thanks for the help guys, and if any one knows any info that might debunk this theory let me know before I hunt this kit down please..

Well, I would have thought that your old pump's venturi would have worked with this one (assuming it is still there), but you would have thought that the literature with the pump would have mentioned it. But you would think they would know what they are talking about. Best of luck to you!

Sorry I haven't posted back just been really busy. But I did fix the problem. And I will say that the people who manufacture the pump were right. I replaced the twin injector and ventory tube and the pump primed write up. I'll say I was happier than a kid a Christmas time. So that should help any one who has any future problems. And thanks for all the help from the people on this forum...

Glad it worked out for you and thanks for posting the result.