We have a 3/4 HP jetpump and a 19 gallon pressure tank hooked up to a 2500 gallon watertank and then going into our little house for about 8 years now. We replaced the pump about 4 years ago and the tank didn`t hold pressure anymore after 8 years, so we bought a new one. Now... we repositioned the pump and a brandnew flotec 19 gallon pressure tank from Homedpot to a new location with new plumbing. Now, everything works perfect, as long as the pump runs , enough pressure... BUT whenever the pump tries to shut off, it just constantly clicks on and off. We raised the shut off pressure, so that it won`t shut off anymore , to avoid the continuously on and off clicking and we unplugged the pump. We bought a new pressure switch, installed it and it does exactly the same thing. The pump works fine, we bought a 30/50 pressure switch, reduced the pressure in the tank to 28, as the tank tells us. We believe, that we might have the system hooked up wrong? Or any other suggestions? We tried to find shematics, but can`t find nothing on the internet, we are baffeled right now. Thanks from Texas

Are you certain there is a checkvalve between the pressure tank and the pump? If there is not, or if it is defective, the water in the pressure tank will simply flow back into the storage tank every time the pump cuts off.

Could also be a waterlogged tank. To check for that, press the little air valve at the top of the tank for a few seconds. If water comes out, then your tank is screwed. But my bet is on a checkvalve problem.

We don`t have a checkvalve, never had one on the previous system, that worked well for 8 years either. We think it`s the system set up, we did something wrong with the pipes?? We keep looking and it`s not clicking with us. About the tank, we had already released air and no water came out, just air...

If I am understanding your correctly, you have a large holding tank. You have one pipe leading from the pump to the holding tank, and another leading from the pump to the pressure tank. You pump water from the holding tank into the pressure tank, and from there it goes to the house. So, your holding tank basically serves as a well. Every system I know has to have a check valve, generally between the pump and the pressure tank, to keep water from the pressure tank from simply flowing backwards back into the holding tank. I'm wondering if, with the changes you made, you did not notice the CV.

This site has a very nice description of the process.

Water system check valve location & purpose - private pump and well system do-it-yourself repairs (http://www.inspectapedia.com/water/CheckValves.htm)

I appreciate your responses and I think I know now... :-) no, never had a checkvalve, the first installation was done by us, too, but, for this one, we first had a "back up pump" and instead of redoing all new lines, we cut into the old ones and connested them and here is, what I think the problem is, the line, coming from the 2500 gallon tank goes to the pump and it splits to the pressure tank, too, instead of a line going to the pump and from the pump to the pressure tank, the pressure tank also has a connection to the storage tank... is this the problem?? We better redo all the lines , we just kept on staring at everything and it seems, that we had a brain/sight block, always bad to cut old lines and hook the new in the old...

You have found your problem. I would think you could simply cut the pipe connecting the two tanks and cap them, then put a CV between the pressure tank and the pump, and you'll be in business.

Will try tomorrow and let you know! Thanks

Good luck. Do let us know how it turns out.

Total frustration right now, we just redid it, a line , coming out of the 2500 gallon storage tank, going solely into the pump, coming out of the pump, going into the pressure tank and out to the house lines... as soon as pump shuts off, pressure goes down from about 40 with a loud swooshing sound... instant pressure loss. One thing, my frustrated brain can think about, did we hook up the lines on the pump wrong? Water in/water out? Horizontal one is hooked up to the 2500 gallon tank and the other one out to pressure tank...

On most jet pumps, the center pipe goes to the water source, while the pipe at the top goes to the pressure tank.

Think about it. When the pump cuts off, what will prevent the water in the pressure tank, at 40# of pressure, from simply flowing backwards into the holding tank?

Put in a checkvalve. Many jet pumps have a built-in check valve. Yours might have, so you haven't notices an external one. But you can be certain there is one somewhere. Not there so can't be real sure, but I'd bet the whooshing sound you are hearing is the water from the tank running back through the pump into the holding tank.

That`s what we figured... will get a valve :-) it just never did this before, same pump, never ran back, maybe there is one in the pump, but it broke?

Could be. Hard to say. Could've been one on a piece of pipe and you inadvertently cut it out when you redid things. Who knows. Let us know how it works out. I can assure you that, if the CV works, then the sense of accomplishment will almost make the aggravation worth it.

I had the on off problem, after a new pump and check valve, discovered a pluged discharge pipe. A critter had droped about four acorns into the priming hole, just the right size to plug that half inch pipe. Duct tape the open system during fall draining.

I had the on off problem, after a new pump and check valve, discovered a pluged discharge pipe. A critter had droped about four acorns into the priming hole, just the right size to plug that half inch pipe. Duct tape the open system during fall draining.
Well that's a new one!

A critter had droped about four acorns into the priming hole
Pumps come with a plug for that opening, What was it doing open?
Back to you, Tom