New jet pump install in basement, but pump won't turn off after hitting cutoff pressure

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Posted by: from Sooke
9/21/2013 at 5:09:44 PM


I'm working on installing a new 1/2 hp jet pump for my father-in-law since his old pump died on him. I've done this before for him a couple of times over the years, so I do have a bit of experience with setting it up and knowing what to look for.

He has an atypical setup in that his house runs on a shallow well that is a couple hundred feet from his house. Thus, he has set up two jet pumps connected in series with each other, one at the well house (which is running fine) which pulls the water from the well and pushes it to the house, and one in the basement (the one I've replaced) that takes the water and gives it that extra push to the rest of his 2 story house.

When the basement pump is shut off at the breaker, the pressure gauge on it reads at around 40 PSI, which is around its normal range. As soon as I supply power to the pump, the pump immediately turns on and the pressure skyrockets to over 100 PSI and stays pinned there until I shut off the breaker, at which point it comes back down to a reasonable level. The weird thing is that when the pump is on and the pressure rises, I can hear the pressure relay switch click as the metal contacts pull away at the expected cutoff pressure (I set it at approx. 60 PSI), but the pump keeps on running and the pressure builds until the pressure gauge is pinned. What's baffling to me is that I can hear the relay click on and off at its expected cuton and cutoff pressures, but the pump doesn't turn off when it's supposed to.

Any help would be greatly appreciated.


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Date/Time9/21/2013 at 6:53:42 PM


The first thing that comes to mind is that the new pump has a faulty shut off relay. It may "click" but may also bounce back t the on position. I'd take the unit back for a replacement or buy a new relay component.

You mentioned this is a replacement so I am assuming there was a similar set up before. I'm not sure why you have two shallow pumps when one should do. Unless the one at the well house is just too small to handle the water load.

I used to have a system on a shallow pump and it ran fine. I connected it from a cistern to the pump to a pressure tank and then to all the plumbing. In you case, the first pump just may be getting the wrong message to the second pump and the relay doesn't understand the differences in water pressure. A shallow pump should pull water from a shallow area and be able to push it (or lift it) a fair way. As mentioned, the size of the pump matters.

I hope this provides a little insight.



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Date/Time9/22/2013 at 9:27:15 AM

Besides the fact that you have a very overly complicted system. I would check that the cut off relay is actually disconecting, the click you are hearing might just be the solenoid just trying to move the contacts. It may have been damaged by the previous pump. Some switchs you can take the cover off and see if they are actually working.

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Doug in Sooke
Date/Time9/22/2013 at 6:04:59 PM


Thanks for the replies, I've now figured out why the pump wouldn't turn off after hitting its cutoff pressure: The relay switch was incorrectly wired, which was my fault. I've now rectified it, and now the pump is switching off as expected when hitting its cut-off pressure.

However, now I've got a more serious problem...the pump at the house is now switching on and off too often, once a second...and I'm finding that the only way to lengthen the time between the switching interval is to turn the cut-on/cut-off nut on the relay switch enough so that the cut-off pressure is in the 70-80 PSI range, that has it switching on/off every 3-4 seconds when running an upstairs tap or flushing a toilet. But I'm finding that the pump is running abnormally hot when operating like this, and it's to the point where it's tripping the breaker at the junction box in the house if we try to have a shower or do a load of laundry.

I asked my brothers-in-law about this kooky setup (as they used to help their dad maintain it before I was around), and while their memories were sketchy on the details, they did recall that they had to do some sort of "synchronization" between the two pumps so that one pump's cut-on/cutoff was slightly different than the other. Of course, they can't remember which one (well or house pump) was set to be higher than the other.

Any ideas on how a setup like this would work? Or at least why the house pump's pressure is going so high as soon as the water's turned on in the house?

Thanks again.


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Doug in Sooke
Date/Time9/22/2013 at 6:14:34 PM

One other thing I forgot - the well pump is a 3/4 hp convertible jet pump, set up in a deep pump configuration (though the water is around 18-20' from the surface).

Also, the well pump is around 250 feet from the house, and the basement pump is in the basement of a two story house.


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Jeff from Newson Interiors in Dunrobin
Date/Time9/24/2013 at 5:34:21 PM


Short cycling is more than likely the fault of the pressure tank. If its cushioning bladder is torn or air space is not there it will cause what you are experiencing. Raising the pressure is not going to solve the problem.

If running 2 pumps you must ensure that the lower pump comes on first and off last to ensure the upper one doesn't starve for water.

I agree with James in that the system is way to complex. My suggestion is a 1/2 HP submersible pump and a new pressure tank. Be sure to size the pressure tank according to your demand and usage.

Hope that helps,


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