Varying pressure from well...............

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WoodMann

WoodMann

Minister of Fire
Feb 9, 2008
670
New Mexico
Should be so fortunate that it's my well. Anyways- GF's house is on a well and lately the pressure very noticeably varies; sometimes to the point of frustration. askin' around a bit somem have metioned of a bladder needing to be bled but looking (maybe I don't know what I'm mlooking at) don't see a bladder. Just a tank. We've been thru a drought and in the subdivision I live in there are restrictions; like can't wash yer car etc.... But we've had some good rain lately.................
Thanks fer ya'lls suggestions, much appreciated....................
 
Sounds like the pressure switch is not doing its job. About once a year, I have to remove the ¼" tube that goes to the pressure switch and clean out the port in the pump housing. It gets clogged and doesn't allow the pressure changes to get to the switch.

Checking the pressure in the tank, as mentioned already, is a good idea, too, but keep my experience in mind.
 
Not an expert, but I have lived with well water for most of my life.

Is it the longer you run the water, or is it kind of jagged all the time? If its a long, steady drop then it could be the differential of the flow switch (but I doubt it). If its starts to drop off after 30-60 seconds it might be the impeller of the pump has worn down and is not pushing enough water. Lots of different things. If it happens the same time every day (after laundry/showeres etc) then you've got a problem with the water level in your well.

1. Check the pressure of the tank as suggested. It should be listed/written on the tank. Shut off power to the well, open up a faucet till you lose all pressure and then check it. If you're at zero you can try adding air till you get to the recommended pressure (I think mine is 12psi). This is all part of a balancing act between the bladder and the flow switch, and like I said I'm not an expert.
2. Run the water and listen for a clicking sound as the pressure switch shuts on/off. A rapid fast clicking tells me you've got a problem with the tank. If it doesn't build enough pressure to shut the pump off after a few minutes while the water is running (hose or faucet, you don't need everything on at once) then you may have a problem with the pump, or even low ground water.

The length of time the pump should run is a formula of tank capacity / gpm of the pump. 10gpm to fill a 20 gallon tank would take 2 minutes. Most well tanks hold around 6 gallons so a 45-60 second cylce with no water running is usual. Things to check. Good luck.
 
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btuser said:
Most well tanks hold around 6 gallons so a 45-60 second cylce with no water running is usual.
Click to expand...
I've seen wells with variable speed pumps and the pressure tank is only a fraction of the normal size. Looks more like an accumulator.
 
To add to btuser's good advice - the tank bladder pressure, with pressure drained from the tank, should be 2 PSI lower than the lower setting on the pressure switch: if the low set point is 20 PSI, the tank should be at 18 PSI.

A bad bladder or wrong pressure would cause the pump to switch on and off quite often, which is bad for the pump and switch, since there would be no storage available in the tank.
 
smoke show said:
I've seen wells with variable speed pumps and the pressure tank is only a fraction of the normal size. Looks more like an accumulator.
Click to expand...
Now you're just trying to make this complicated.

He's right, but I've never seen one in a house. Maybe they're cheap enough now, or more common in other places. Around here it's a big blue tank in the basement with 3 wires headed to the pump. No capacitors, nothin' fancy and learn to like what it tastes like.
 
Is this an above ground jet pump, or submersible?? This problem is more common with a jet pump. Air leaking into pump housing, or bad / dirty foot valve at well bottom.

The bladder is like a balloon inside the tank that has a tire valve on top to set the pressure. This air pressure is what pushes the water out, until the water pressure at the switch is low enough to turn the pump on. When the bladder breaks, the solid water without the air cushion calls for the pump to run as soon as water is turned on, and will turn off when faucet is shut off. So the primary reason for the bladder is fewer, but longer pump cycles.
So pressure could be a lot of things. Bad switch, or clogged pipe to switch, or (If a deep well submersible) a wire going down the well to the pump is chaffed against the casing, or cut off. Each time the pump cycles, it tries to twist the opposite direction the rotor turns. There should be anti-torque boots like rubber snubbers to prevent the pump and line from twisting and thrashing against the well casing or rock sides. One wire cut off can allow the pump to run on 110 volts with only one feed wire. Not good for pump. Removing the pump switch cover, and running water to turn on the switch should show a spark at each (2) terminal point on the switch. If only one contact sparks, the entire load is on one leg of the two 110 wires going to the pump. This causes the pump to run slow, overheat, and not always trip a breaker.
 
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coaly said:
Is this an above ground jet pump, or submersible?? This problem is more common with a jet pump. Air leaking into pump housing, or bad / dirty foot valve at well bottom.

The bladder is like a balloon inside the tank that has a tire valve on top to set the pressure. This air pressure is what pushes the water out, until the water pressure at the switch is low enough to turn the pump on. When the bladder breaks, the solid water without the air cushion calls for the pump to run as soon as water is turned on, and will turn off when faucet is shut off. So the primary reason for the bladder is fewer, but longer pump cycles.
So pressure could be a lot of things. Bad switch, or clogged pipe to switch, or (If a deep well submersible) a wire going down the well to the pump is chaffed against the casing, or cut off. Each time the pump cycles, it tries to twist the opposite direction the rotor turns. There should be anti-torque boots like rubber snubbers to prevent the pump and line from twisting and thrashing against the well casing or rock sides. One wire cut off can allow the pump to run on 110 volts with only one feed wire. Not good for pump. Removing the pump switch cover, and running water to turn on the switch should show a spark at each (2) terminal point on the switch. If only one contact sparks, the entire load is on one leg of the two 110 wires going to the pump. This causes the pump to run slow, overheat, and not always trip a breaker.
Click to expand...
Great detail, I think smoke summed it up with the short to the point version.:cool:
 
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Depends on the type of system. I don't assume anything anymore. If it's a two pipe jet pump, and the pick up screen is clogged, it has nothing to do with the pressure tank. That's why I explain how the system works so the person looking at the system has an idea of what they are looking at and can figure out what it's doing or not doing. You can't troubleshoot something if you don't know how it works.
How about a mouse nest sucked against the water inlet screen on a submersible pump ? My neighbor found the conduit pipe outside the casing going into the ground was an entrance for mice. They were entering the well cap with the wires, built a nest on the curled up wires on top, and as the nest material fell in, sunk and was pulled to clog the pump screen inlet. i suggested to silicone the wire entrance shut when putting it back together. (people don't live in or drink the water - it's an alligator refuge - a foreclosed home used for 12 full size and rare gators)
The only time I had low pressure was due to one of the wires getting cut off against the rock, and the pump wasn't coming up to speed. I opened a hose bib and had low volume and pressure. Pulled the pump right away and replaced wires, taping them better to the pipe. I never realized it would start and run with one 110 supply line.

I know it sounds unbelievable to live next to a home full of alligators.... in Northeast PA......
and no pictures, it didn't happen;


http://www.google.com/search?hl=en&...3.0.9.0.1.250.593.0j2j1.3.0...0.0.B20gsQORPfM
 
THanks guys, I'll check all that- I don't remember seeing a schrader valve atop the tank last time open, but I'll look again when I poke around for pressure readings. The pump I believe is 'submersible'. it's one of those that's like half way down the well. I hope ther's a schreader valve up there, just let a little air our and be on with business...........
 
There's a little more to it than letting a little air out. Sometimes the valve isn't on the very top. Larger tanks are on the side, towards the top.
You need the correct air pressure. Run water and watch the gauge to find the cut in pressure when the switch turns on. Shut off power to pump, and drain tank. Pressurize with air to 2 or 3 pounds below cut in pressure. Many instructions for tanks and switches call for 1 pound below cut in pressure. Depending on pressure gauge and air gauge accuracy, 2 or 3 pounds is easier to obtain.

http://keithspecialty.wordpress.com/2011/04/01/pressure-tank-setting-the-pressure/
 
Been through three times since 1975. Adjusting the pressure would last only a few months. For me, it was always a case of the bladder in the holding tank failing. Solution, replace the tank, the pressure switch and the gage. Really not that costly and it will end your pressure issues for a few years. My son did the last switch over in a little under two hours. About $200.
 
Lack of air in the pressure tank bladder is the most common cause of short cycling and varying pump pressure. I have a friend that bought a property in which the previous owner had replaced switches and relays constantly, but never checked the pressure tank. The bladder was at 0 psi. We filled it to 25psi a year ago and it's been fine since then.
 
The cost of electricity in a short cycling tank is just awful. My bill went up nearly $50 a month until I fixed the problem. you know it is bad when the pressure cycles down and up repeatedly while you are in the shower.
 
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