Well Pressure low ... Any idea's?

   / Well Pressure low ... Any idea's? #1  

blueriver

Super Member
Joined
Oct 4, 2007
Messages
5,025
Location
S.E.Oklahoma
Tractor
JD 5520 Montana 4340 Farmall Super A Montana 5720C
The place I bought is on Rural Water, I found the old well. It is 75' deep in a
5" casing with the water level at 15'. I bought everything I needed (used) put the submersible pump in at 65' hooked everything up put 20 PSI in the tank thru the switch and am pumping water. The switch is set at 30 and 50.

The pump kicks on, pressure builds to 50, water flows, pressure drops to 30 pump kicks back on. The first few days excellent pressure at the end of the hose and the past few days low pressure at the end of the hose ... I checked the water level and after the rain I am now at 10'. Everything appears to be working correctly, just low pressure from the hose. Do I need more air in the tank?
 
   / Well Pressure low ... Any idea's? #2  
check to see if your pump is running constantly
larry
 
   / Well Pressure low ... Any idea's? #3  
The place I bought is on Rural Water, I found the old well. It is 75' deep in a
5" casing with the water level at 15'. I bought everything I needed (used) put the submersible pump in at 65' hooked everything up put 20 PSI in the tank thru the switch and am pumping water. The switch is set at 30 and 50.

The pump kicks on, pressure builds to 50, water flows, pressure drops to 30 pump kicks back on. The first few days excellent pressure at the end of the hose and the past few days low pressure at the end of the hose ... I checked the water level and after the rain I am now at 10'. Everything appears to be working correctly, just low pressure from the hose. Do I need more air in the tank?
I have always been told the bladder tank air pressure should be 2 psi under the cut-in pressure, or 28 psi for a 30 - 50 psi switch.
 
   / Well Pressure low ... Any idea's? #4  
Given that you bought used could the bladder in the pressure tank be bad. Have you put a gauge on it to see if it holding air pressure?

MarkV
 
   / Well Pressure low ... Any idea's? #5  
I have always been told the bladder tank air pressure should be 2 psi under the cut-in pressure, or 28 psi for a 30 - 50 psi switch.
That is what I've always gone by. The pressure is measured without water in the tank, drain the water off first.
 
   / Well Pressure low ... Any idea's? #6  
You said "low pressure at the end of the hose", you did not say what the pressure gage said. If it is still saying 30-50 I'd look somewhere else. What about the rest of the faucets in the place, are they slow also? If the pump pumps up to 50 and shuts off, it does not matter if the bladder is bad or not, you still should have pressure at the hose bib.

DRL
 
   / Well Pressure low ... Any idea's? #7  
two more possibilities:

1. there is a leak in the down pipe above the tank causing the pump to run all the time without building pressure.

2. the well simply can't keep up. the pump pumps the water, builds pressure, the water level in the hole drops below the pump, pressure drops as pump pumps air. this is very common with shallow wells like yours because the volume of water in the well hole itself is not much larger than a big tank. the water may trickle back in and refill, but due to the low surface area of the relatively short hole and the small volume of the hole, you only get a couple of hundred gallons before it goes dry and has to refill.

either option is bad on the pump.

if option 1, fix the leak.

if option 2, but in a storage tank you can slowly fill at night or whatever and then pump from that to increase your capacity. or dig a deeper well.

low bladder pressure will cause the well pump to cycle more often. that is why the bladder is there. the bladder pressure must be matched to the pressure switch cut in and cut out values for your set up. not equal to them, but "matched" so that the pressure tank holds a good volume of water (the bladder is compressed) when the pressure switch hits the upper cutoff, then the bladder can expand and force the water out while the pressure drops to the lower pressure switch cutoff and the pump kicks back in and the whole process starts over again.

once you eliminate option 1 and 2 from consideration, you may have to experiement with a bucket and timer to get your pressure tank bladder correctly balanced. if it's hot and humid, you might also get the level by looking for the condensation line on the outside of the pressure tank.

for reference, in one of our systems, the bladder tank (when the pressure tank is completely empty of water!) runs about 28 psi gauge at the fill nipple with a pressure cut in value of 30 and cutoff of 65 psi for the well pump. this gets us a pressure tank about half full when the pump kicks off at the upper limit. this agrees with the other poster's info on 2 psi below the cutin pressure.

amp
 
   / Well Pressure low ... Any idea's?
  • Thread Starter
#8  
The pump cycles as it should on at the low end and off at the high end, it does not run constantly. The well is not hooked into the main line, yet, so there is only one hose bib the flow remains the same at any gauge reading. I will check the tank with a gauge. I am inclined to believe the well simply can not keep up, perhaps that is why "I found it" there was no metion of it when I bought the place... Thanks for the imput.
 
   / Well Pressure low ... Any idea's? #9  
if the pump is able to maintain the set points (50 at cutoff and 30 at cutin) and doesn't leak down when all outputs are off, then you have an obstruction in the line between the pressure gauge and the outlet hose. i would look especially close at valves that may have loose casings or clogs behind the shut off washer or a mangled washer.

at 50 psi, the pressure should shoot a nice, solid stream about the diameter of a nickle a good 5 or more feet from a 5/8" hose. if you're not getting something like that, something is up.

it sounds like you have yet to pump the well dry since you have a good water level and the pump is holding the pressure. once it starts to suck air, the pressure will drop drastically.

amp
 
   / Well Pressure low ... Any idea's? #10  
The pump cycles as it should on at the low end and off at the high end, it does not run constantly. The well is not hooked into the main line, yet, so there is only one hose bib the flow remains the same at any gauge reading. I will check the tank with a gauge. I am inclined to believe the well simply can not keep up, perhaps that is why "I found it" there was no metion of it when I bought the place... Thanks for the imput.
I think the waterbag in your tank is blown, leaving the bag deflated because the water goes right thru it and gets on top. The water is kinda trapped in the tank by the deflated bag. When you 1st turn on the hose does it spurt then trickle?

Try this. Turn off the pump and run the water out of the hose til it totally stops - ever how long it takes. Then turn the pump on while leaving the hose on. Does the hose run fast?
larry
 
 
Top