New pump woes

[kron3007]

Yesterday morning I woke up to the reality that my jet pump was not working. After replacing the switch, I discovered that the pump was blown. I bought a new 3/4 HP (the same HP as the previous one) jet pump and installed it.

After everything was hooked up I proceded to prime the pump (with some difficulty). However, the pump pressure usually only goes up to about 20 psi (instructions said it should go to 30, then adjust the control to set it a 25). Often when I turn on the pump it does not get any pressure at all, but when I open it, it still has water in it. Other times I will have pressure and it drops down and comes back up. Another problem is that the water tank will not go above 30 psi (made it to 38 once), and it seems that it may not be holding pressure to well.

One other thing that had occured to me is that the pressure tank may be watterlogged. So I emptied most of the water out of it. Turns out I emptied too much, so I filled it back to the point where it would no longer push air into the pump when the tap was open. One question that I have is, do I need more water in it? Now whenever I try to open the pressure tank I lose all pressure in the pump. I am trying to opejn the tap very slowly, but I lose all pressure imediately.

Another thought that I had was that the foot valve could be clogged. Would that result in the inconsistent pressure that the pump acheives?

Any way, I'm not sure what to do. If anyone has any insight it would be appreciated.

[kron3007]

One other thing. The pump came with a piece that connects the two pipes to one and a foot valve (with a venturi tube or something?). Are any of these pieces specific to different brands and need to be replaces along with the pump, or are they interchangable? I did not want to pull the foot valve and pipes unless necessary, so I left the old ones.

[Bob NH]

Was the old pump a shallow well jet or a deep well jet? From your latest post it sounds like a deep well jet. The link below provides a description of a deep well jet installation and start-up.

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex639?opendocument

If you have a deep well pump, you should consider replacing the bad pump with a submersible pump if the well is 4" or larger.

[kron3007]

It was/is a deep well jet. They are the same HP, so I thought that it would be suitable. Perhaps a submersible would be better, I was just going with what was there before. The previous pump lasted quite a while, is it worth switching to a submersible (I will need to look into the depth right?). When you say 4" are you talking about the well hole (it looks about 4")

[Bob NH]

The inside diameter of the pipe must be at least 4" for a standard submersible. They are about 3.75 diameter and will work in a 4" pipe. Schedule 40 steel pipe is 4.50 outside diameter and 4.02" inside diameter.

You would have to remove the pipes inside the well.

A submersible is much more efficient than a deep well jet and has no problems with priming.