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Alan 09-01-2006 11:20 AM

Help me understand my well...
Exactly WHAT PART of the system ACTUALLY determines the pressure?

My well was working pretty good (pressure wise) until the plumber came to replace some of the parts on my pump that went bad. He said the pressure in my pressure tank was TOO HIGH, my switch was a 20/40, and my pressure tank should be charged to 18psi always 2psi before cut in pressure.

Now when I take showers in the morning, I can DEFINITELY tell when the pump is about to come on, because the pressure will be pretty low for about 5 minutes prior. Its enough water to shower with really, but its low enough that it takes a lot longer to rinse your hair out, which is pretty bad considering that I cut my hair to 1/8".

Anyway, here's the way I THINK it works..... pump (jet pump) pulls water from the well, and fills the pressure tank up until the pressure in the tank is 40psi. Once the tank gets down to 18, the pump will kick back on and repressurize/fill the pressure tank.
What i'm confused on is what is actually determining the water pressure. It seems that adding a more powerful pump will only reduce the time it takes to fill the pressure tank. Since the plumber said always 2psi below cut in pressure, I'm thinking that a new pressure switch would allow me to put more air pressure in the pressure tank?

I've even lost myself now. Gah....... :wacko:

Mike Swearingen 09-01-2006 02:17 PM

Well water pressure is determined by a number of factors (that's why its called a "system"), and you have the basics of how it works down o.k.
If the well has enough water capacity to provide the volume and your pump can pump it, you may be able to increase your water pressure by increasing the 20-40 psi cut-on/cut-off to 30-50 psi by adjusting the pressure switch and airing up the bladder tank to 28 psi.
The pressure switch may have a single adjusting nut, or there may be two. The single nut automatically adjusts the on/off pressure 20 psi apart. The larger (taller) adjusting nut on a two-nut switch adjusts the cut-on and the shorter one adjusts the cut-off. You have to experiment to find the right pressure for your system.
Be careful when adjusting the switch because the hot wires/connection screws are exposed and can electrocute you if touched.\
Great tutorials:
Good luck!

Alan 09-01-2006 07:01 PM

Its a single nut switch, but i'm not sure whether the pump can pump it or if the well has enough volume. :whistling2:

Would it be dangerous/stupid to try adjusting them without knowing? Worst case is to have to readjust the switch and deflate the bladder in the pressure tank, right?

I honestly don't even know how i'd know what i'm adjusting the nut to when i'm turning it anyway. :no:

Mike Swearingen 09-01-2006 07:20 PM

It won't hurt anything to try to adjust it to see what your system can do.
Just turn the pressure switch nut down to increase the pressure. Back it back up a bit if the pump "labors" too much to build the pressure or if it won't cut off at all, until you get it working better.
Once you get it working better by adjusting the pressure switch, then air up the pressure tank to two psi below the cut-on pressure with a bicycle pump or portable air tank or compressor.
Just experiment with your system to see what it will do.
Good luck!

Alan 09-04-2006 02:27 PM


Apparently I was mistaken. The old switch was a single nut style, apparently he put a new one on to accomadate a different type of hose. Screw on fittings on both ends instead of the little black plastic tube that was there before. Anyhow, I bumped my pressure from 20/40 to 24/44 and voila! Works great now. I am impressed how much difference that tiny bit of pressure made.

Still confused on why the need for a specific amount of pressure in the pressure tank though.

Anyway, thanks for your help :)

Mike Swearingen 09-04-2006 07:01 PM

Just add air until the pressure tank psi is 22, if you're happy with the 24 psi cut-on.
I can't tell you "why", I just know that that is what I've always heard to do with the pressure tank adjustment, so I follow it. Works for me.
Maybe you can find a "why" on either Ron Peeks' or Jess Stryker's site.
They're the experts, not me.

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