Strange well problem

[Patrick Bishop]

Other forum posts have come close to but not exactly to describing our symptoms, so hoping someone here can help diagnose our problem.

In the last few weeks, this has been happening intermittently.

1. Open the tap and either nothing comes out, or it runs only for a minute or two. After it starts back up, it does so:
a. only for a few minutes,
b. with fluctuating pressure,
c. with a brief, violent spurt that SOMETIMES includes sediment (iron, apparently, not dirt).

When I say "intermittently," I mean sometimes hours or days will go by without this happening, and sometimes hours or days will go by in which this is all it does, which is very confusing as I try to figure out what the problem is.

My mostly-inaccessible water pressure tank (installed under the stairs when the house was built) has a red label saying it was factory pre-charged with air. Am I right in thinking this means it's a bladder-type tank? Below the label, there appears to be a red rocker switch, the function of which is a mystery to me.

Since the garden hose is also affected, and since bypassing our Rainsoft water treatment system did not affect the problem in the rest of the house, my best guess is that something is going wrong with the pressure tank, the well pump, or both.

Let me thank you in advance for your advice regarding what the most likely causes of this problem could be, and what I can do to fix it myself, since major parts and professional service are way outside our very limited budget.

Regards from Rural Spotsylvania, VA
Patrick Bishop

 

[Valveman]

I don't know what the "red rocker switch" is, but it is probably a captive air tank. If you haven't checked the air charge in several years the bladder is probably busted. Then the tank is waterlogged, the pump rapid cycles and stirs things up for a few minutes, the overload in the motor trips, and the water stops. A few minutes later the overload resets itself and the process starts all over again.

Check the air charge in the tank while the power is off to the pump and the tank is empty of water. If there is no air pressure or water comes out the tanks air valve, the bladder is bad and you need a new tank. You need to replace it with another tank at least as large as the last one, or you can switch to a small tank if you use a CSV.

 

[Sponsor]

 

[Reach4]

My mostly-inaccessible water pressure tank (installed under the stairs when the house was built) has a red label saying it was factory pre-charged with air. Am I right in thinking this means it's a bladder-type tank? Below the label, there appears to be a red rocker switch, the function of which is a mystery to me.

The better pre-charged pressure tanks use a diaphragm rather than a bladder, but many call both kinds bladder tanks.

While it is not causing your problem, you should check/adjust the precharge on your pump.

Do you have a submersible pump down the well, or is your pump not down the well? I presume submersible, but I am not sure.

I see Valveman has posted since I started typing.

I doubt your well is running out of water intermittently; valveman did not mention that, and he has experience.

 

[Patrick Bishop]

I appreciate everyone's input.

I am dubious that it is the bladder in the tank itself, though it could be. When a bladder/diaphragm fails, shouldn't the symptoms appear all the time? Our symptoms come and go. The thing may do this for days, every time we turn on a faucet or take a shower. Then there are days during which there is no indication that anything is wrong. If the bladder/diaphragm fails, will it really produce a symptom only sometimes, or should it produce the symptom all the time? This is what is so puzzling to me, since this is the first time I'm having to learn about these well systems.

There is a lot of iron and sulfur in our well water. Could these chemicals be causing valves leading into/out of the pressure tank to sporadically malfunction?

Again, I appreciate your time and effort advising me.

 

[Patrick Bishop]

The better pre-charged pressure tanks use a diaphragm rather than a bladder, but many call both kinds bladder tanks.

While it is not causing your problem, you should check/adjust the precharge on your pump.

Do you have a submersible pump down the well, or is your pump not down the well? I presume submersible, but I am not sure.

​

It is down the well. I am nervous about monkeying with it. Can you post a link to the procedure and tools?

 

[Reach4]

Get a pressure gauge, and a tire pump in case you need air.
(optional step: with water pressure normal and the pump not running, measure the air pressure and compare with the water pressure gauge. These will usually be pretty close in pressure normally. The main point of this optional step is to compare calibration of the two gauges) If water comes out of the valve, your diaphram/bladder has a leak, and your tank will need replacing.

Turn off the power to the pump. Open a convenient cold faucet (lower is better) to let the water pressure to drop to zero or nearly zero (0 PSI). Confirm that the water pressure gauge now reads zero or near zero. If that gauge does not, replace that gauge and/or the nipple going to the gauge.

The air pressure precharge when using a submersible pump is normally set to 2 PSI below the cut-on pressure. That difference is to give the pump time to react once the pressure switch turns on the pump. It also allows for a slight calibration difference between the air pressure gauge and the water pressure gauge. If you had a jet pump, 4 PSI would usually be a better differential, since the jet pump takes longer to build pressure.

Close the faucet that you used to drain the water, and turn on the power to the pump. While you are at it, this would be a good time to record how long it takes for the pressure to reach the cut-off pressure. A minute or more is desired.