View Full Version : Increasing well pump pressure... Little help here...

06-29-2011, 07:46 AM
My house has a jet pump well setup... I believe its a 1/3hp motor... Currently, it has a 30/50psi switch on it... I thought easy enough, i'll switch to a 40/60 and get more pressure... I couldn't get my pump go go above 51psi... Why is this? My pump has a feed & a return, not just a feed like some older jet pump setups... Is too much water just being returned into the well?

Oh, and my bladder is at 27psi... It was at like 3psi, so I filled it, and that just seemed to make the pressure more steady...

06-30-2011, 11:03 PM
Jet pumps are usually centrifugal pumps and the maximum pressure is a function of the depth of the well and the impeller design.

If the pump is not capable of pumping more than 51 psi, then changing the switch out won't make a difference except the pump will run forever since it can't reach the high cutout. It will probably self destruct in some fashion if you don't use the proper switch.

Don't you have a manual?

07-01-2011, 06:51 AM
Nope... The pump was here when I bought the house... I had a plumber tell me he could just change out the switch, which is why I tried it..

I'm also wondering if i need to pull my well pipe up some... I live in a high clay base area, and my filters turn brown within 12 hours of being replaced, and need to be replaced every 4-6 weeks because they get so caked water pressure drops...

07-01-2011, 07:11 AM
Is the pump at ground level or down the well? If it's above ground, there should be a tag on it and you may be able to find a manual for it.

07-01-2011, 07:44 AM
The pump is in my laundry room, as its a jet pump, not a submersible... Its a craftsman 1/3hp...

07-01-2011, 08:03 AM
Good Luck, we had a small above ground like that, the one we had had a max output of 50psi. With the switch adjusted for the max it just ran almost nonstop, would only stop when no water was being used.
Finally gave up and switched to a larger pump rated for the higher pressures.

07-01-2011, 09:19 AM
I just replaced my old, leaking 1/2HP Craftsman jet pump with a new 3/4HP unit.

The old one was 30/50psi, new one is 40/60psi. I knew the old pump wouldn't make it to 60psi because going from 49psi to 50psi took too long. It would have taken it another hour to go from 50 to 60, I think! :)

New pump gets to 60 in no time.

I also replaced my rusty (from the outside) bladder tank. Went from 19 to 35 gallons so the pump doesn't have to start/stop so much.

I got my pump off eBay for $110 shipped, lightly used.

I'm loving the extra 10 psi. Makes a world of difference after going through a whole house filter (10 micron) and a water softener.

07-01-2011, 08:09 PM
hmmmm... I may have to do that... How much of a bitch was it to re-prime the system?

07-02-2011, 11:04 AM
None at all. Just make sure you fill a couple gallon jugs of water before taking stuff apart.

The pump housing takes almost a gallon by itself.

Fill the "from well" pipe with water before connecting it to the pump, since the pump has a check valve in it that will keep water from draining back into the pipe.

Then fill the pump housing and button it up. It should start pumping within a few seconds of powering it on. You'll hear the pump start to work harder when it starts pumping.

07-02-2011, 01:26 PM
lametech has the idea.

One thing to watch for is leaks, depending on how old everything is, you may be pushing the limits of some joints and faucets.

09-06-2011, 10:49 AM
lametec... Did your pump also have a return? Im curious because mine does, and wondering if maybe the pump is just returning too much...

EDIT: Now I'm wondering if its pressure, or VOLUME that I need to be looking into.. Maybe the pump just isn't moving enough volume? When the pump is on, it does sound like there is a little cavitation going on... Not much, but definitely doesn't sound like the pump is 100% full... Could that be an issue?

09-06-2011, 12:04 PM
You're going to have to explain "return".. Do you mean back into the ground?

In any case, there's no return on mine. On the output manifold of the pump it there's one hose going to the bladder tank, another to the house piping.

Edit: Did some googling. A two line jet pump is for deeper wells, it seems. It's not a "return" per se, but rather one hose of "the loop". The water doesn't go back into the well, but rather makes a loop down, then comes right back up. See diagram:

It's not a matter of volume. If you're not using any water, no matter how little volume the pump is moving, the pressure in the tank will eventually rise.

Like I said with mine, though, my original 1/2 hp pump I don't think would ever have got much higher than 50 psi. The new 3/4 hp on passes right by 50 psi at about the same rate the 1/2 hp passed 40 psi.

With yours being a 1/3 hp pump, you might just not have enough motor (and pump size) to go to higher pressures. Call the mfg and see what they say about max psi rating for your pump.

09-06-2011, 12:22 PM
I have the same question as the OP since I would like to boost output pressure at the pump maybe 5psi to compensate for additional head trying to push the water uphill to the building (maybe 10' higher than the pump).

For what it's worth, I'll share a few things I learned about above-ground well pumps a while ago when I needed to get water flowing out at the Asylum. The property had a pipe in the ground but the pump/tank had been removed a few years prior due to some property sub-dividing. So I needed to install a well head, pump, and tank.

My pump setup is what they call a "deep" well, and has two pipes. It has a outer casing (actually being used as one of the flow paths) and an inner drop pipe. Anytime the pump is running, water is circulating down the well to the nozzle and back up again. A venturi is attached at the bottom of the inner pipe and as water is circulated, new water is drawn in at the venturi to make up for the water being pumped out at the top and being ultimately used.

I remember having to choose the proper venturi nozzle to install down in the well to match my pump flow/hp and height of draw. This circulation is needed so the pump doesn't have to draw this large column of water up the deep well. Water that is drawn up is basically balanced by the water being circulated down and the "net" amount being lifted is essentially only the relatively small amount of water being used in the building. I thought is was a pretty cool concept.

09-06-2011, 12:27 PM
You're going to have to explain "return".. Do you mean back into the ground?

Oops - you must have posted this while I was writing. The diagram shown is a "deep" well as I was explaining. If there is only one pipe from the pump to the well head, it is a "shallow" well and the pump must be capable of drawing the water up the entire distance.

Charles (in GA)
09-06-2011, 01:15 PM
Bladder tank pressure must be set at about 2 to 3 psi BELOW the pressure switch cut on setting. If you have a 30/50 system, open the pump circuit breaker so it cannot operate, open a faucet or two and leave it open to relive pressure in the system. Leave it open. carefully adjust the pressure in the bladder tank, and when it is stable at 28 psi for a 30 psi cut in switch, then close the faucet and switch the breaker on and let the pump build up pressure.

If the bladder is set above the pressure switch cut in, the water will flow till the tank is completely empty, and suddenly will quit flowing, and at that moment, as the pressure falls off, the pressure switch will switch the pump on, and the pressure will come back up. Its annoying to have this happen in the shower, so keep the tank pressure below the switch on setting.


Ohio Auto
09-06-2011, 01:36 PM
Also...if your pressure tank is seperate from your pump...and it was down to 3 psi...I would change it out while you're working on things.

A leaking bladder on a pressure tank is the number one reason well pumps fail prematurely.

Milton Shaw
09-06-2011, 03:13 PM
Shallow well is basically a well about 25 foot deep or less. The max amount you can suck water up from a well is about 33 feet with a perfect vacumn. So the deep well jet siphon pump is designed so that the venturi actually acts like a pump at the bottom of the well to overcome the 25 foot limit. The electric submersible pump at the bottom of the well over comes the limits of both the jet and shallow well pump. The only above ground part is the controls and the tank. It looks like it would be the better way to go to more pressure/volumm. Nothern tool has several in their current catalog with 3 year warrenty, you might check them out.