Air lift water well brain pickin thread

[greybeard]

The young couple near me has a water well that uses a little compressor to lift water out of the well bore. I'm familiar with how the down hole part works but they have a volume tank the well empties into and inside the tank, is a submersible pump that supplies water to a little pressure tank. Float valve inside the storage tank cuts the compressor off and on as it should.
That sub pump inside the volume tank tho, runs all the time. Been that way evidently, for months and their elec bill is thru the roof.
I haven't really looked at it closely, but my first thought was the little squareD pressure switch that controls the sub pump was bad, but my next question, was where the heck is the water going the sub pump is pumping?
Is there a popoff valve inside those volume storage tanks and the sub pump is just recirculating the same water?

 

[Lee VanRoss]

Check to see if you are missing a pressure switch or if there is one try to get a pressure test. Confirm with the manual.
Logically a pump cannot maintain a constant 35 lb of pressure without a bypass to the main chamber. Good Luck

 

[Lee VanRoss]

Check to see if you are missing a pressure switch or if there is one try to get a pressure test. Confirm with the manual.
Logically a pump cannot maintain a constant 35 lb of pressure without a bypass to the main chamber. Good Luck

After looking at this in more detail I would definitely check the setting on the float switch..

 

[greybeard]

After looking at this in more detail I would definitely check the setting on the float switch..

The float switch only controls the air compressor in order to maintain water level in the volume tank. Depending how the float switch fails (always stuck open or always stuck closed contacts), the compressor would either run continuously or never come on and volume tank either run over or would run out of water as the household uses water.

My initial guess is maybe the piping just above sub pump is cracked or there is a popoff valve above that pump that is partially open and leaking by just enough to keep the sub pump's squareD control switch contacts from opening but I couldn't see down below the water surface in the black poly volume tank.

(I'm trying to help the younguns out a little as both are out of work right now due to he having covid since a few days before Christmas. He is improving daily but is not allowed back to work as he works in a medical facility in Houston. $$ is tight with them right now I'm sure and getting someone out to fix it is not going to be cheap)

The sub pump inside the tank is just controlled by the same kind of switch most of us are familiar with. 2 screw adjustment SqD box switch. Looks just like this one.

 

[Ouachita]

On a conventional submersible pump installation, I had the pipe between the pump and well head crack. The sub pump ran continuously, but still provided adequate pressure to use the appliances. Someone had used the black irrigation pipe down in the well.

 

[simme]

I assume the pump is a centrifugal pump (as opposed to a positive displacement pump). Centrifugal pumps have a spinning impeller with variable flow rate as the discharge pressure changes. Positive displacement pumps produce a constant flow rate at whatever pressure is required to move the fluid (limited by motor hp and relief devices). You can close the discharge valve on a centrifugal pump and the flow will be zero. But it is still running and using electricity. Power used is variable with flow rate, but still uses some at zero flow. The term is that the pump is "dead headed". Producing max pressure, but zero flow. From the data, looks like the pump as it exists today in its installed condition has a deadhead of 35 psig. No flow at 35 psi. Not producing enough pressure to satisfy the pressure switch. Either because the suction is clogged or restricted or the pump is broken or worn out. Corroded or worn impeller on the pump maybe or maybe sucking air on the suction of the pump. Or maybe leaking on the pump discharge in the tank as you mentioned. Every centrifugal pump has a pump curve - a chart of pressure vs flow. Max pressure at min flow and min pressure at max flow. Pump will operate on that curve if it has adequate suction pressure, no restriction on the suction and in good condition. As pumps wear, the "internal bypass" around the impeller increases (think internal leakage). I have probably just added more confusion. Cracked discharge, worn out pump of clogged suction are possible for the problem. Just my thoughts.
If the pump runs without producing flow from the tank, the electrical energy will be converted to heat in the water.

 

[D2Cat]

What Simme explained, submersible pump is wore out using electricity trying to pump but not getting the job done.

 

[Nesikep]

drop the pressure on the sub pump switch until it cuts out, if it cuts back in really soon, maybe there are leaks somewhere, or a check valve is bad.. As Simme said, it might be worn out too.

Do you have valve you can shut off along the way? Like around the pressure tank... see if closing them changes anything

 

[Named'em Tamed'em]

Is there a "foot valve"?

 

[Silver]

I would want to dead head the pump as close to the pressure switch as possible to verify pressure switch function. If dead heading doesn't cause pressure switch to turn off pump then either the switch is faulty or the pump can't make required pressure. Nesi's suggestion of turning the PS kick out pressure down should tell the tale.

 

[greybeard]

I'm thinking, that the near zero weather 11 months ago and no electricity for over 36 hrs may have cracked the pvc discharge above the pump but within the tank. They used quite a bit of water from the tank during those days gravity flow from a valve drain valve lower on the tank for drinking, flushing, general use water into 5 gal buckets and the water level in the tank dropped down to about 1/2 full. Sometimes freeze cracks don't show up for months. May even have cracked the pump case.

I had trouble with my own well about a month ago and filled a 55gal drum with water from his well and he plenty of pressure and flow at that time, but the pump was not shutting off then either. I just assumed they were using water in the house at the same time. He has not noticed any drop in either pressure or flow in his house.
I'll have to look at the thing closer tomorrow or the next day.

 

[simme]

It was stated that the gauge showed 35 psi. But then it recently had adequate pressure and flow to fill a drum. The deep freeze could have damaged that gauge as well as the pressure switch. A gauge in that service is usually a $10 gauge whereas an industrial gauge may be $100. Might want to put a new gauge on there to confirm the pressure and the switch setting/function. From my career in instrumentation and controls, I know that people tend to believe a cheap gauge more so than an accurate pressure instrument. Many gauges do not read correctly especially if they have been pressurized beyond their range or frozen.

 

[wbvs58]

I'd look at the basics first GB, those pressure switches have a small orifice that that the water goes through to the rubber diaphram that operates the on off switch. I have had my pump running continuously like that and it was that small orifice blocked up with a bit of corrosion and debris. Once reamed out and cleaned things returned to normal. I would check that before playing with the settings on the screws. Also does the pressure tank have a bladder with a tire fitting valve to pump up, if so check the pressure there with a tire gauge.

Ken

 

[Brute 23]

Could be a lot of things but I'd start by pushing the contacts on the switch with a screwdriver and seeing if it cuts on and off followed by changing the gauge. Then I would start isolating every valve off the tank one by one. If then it is still running I would say you have to open it up.

 

[greybeard]

I'd look at the basics first GB, those pressure switches have a small orifice that that the water goes through to the rubber diaphram that operates the on off switch. I have had my pump running continuously like that and it was that small orifice blocked up with a bit of corrosion and debris.

This, is a distinct possibility. Had it happen to one of mine years ago myself, and it's a cheap fix as well. Around $30 if I remember right.

No foot valve that I am aware of but if there it, it's near the bottom of the volume tank's sub pump which I couldn't see.

I helped him fix all the freeze busted lines last winter and to my recollection, there is only 1shut off valve in the whole discharge section and it's right before the pressure line enters the house. Piping was not done very neatly to begin with. 1 1/4" lines from the pump go down and are just laying on top of the concrete slab, and part of the 1" after the pressure tank was poly tubing, again just laying on the slab.
Just for info, the whole thing was installed new in mid 2016 by the local well drilling outfit when the home was built and they have a pretty good reputation here. Inside, just the 2 young people, with 2 plain bathrooms, a washing machine, dishwasher, kitchen sink. I was able to look down the cleanout of the drain line that goes to the septic tank to confirm there was no water constantly being used. House is on a slab, no crawl space so if there is a break in the piping somewhere, it would have to be inside the slab or in a wall and I walked all around and saw no water pouring out the outside of the metal siding (it's a 'barndominium') . I was there when the slab was poured and saw how they did the water and sewage lines.

 

[Nesikep]

It was stated that the gauge showed 35 psi. But then it recently had adequate pressure and flow to fill a drum. The deep freeze could have damaged that gauge as well as the pressure switch. A gauge in that service is usually a $10 gauge whereas an industrial gauge may be $100. Might want to put a new gauge on there to confirm the pressure and the switch setting/function. From my career in instrumentation and controls, I know that people tend to believe a cheap gauge more so than an accurate pressure instrument. Many gauges do not read correctly especially if they have been pressurized beyond their range or frozen.

good point on the gauge too.. yeah, they don't like getting frozen either

 

[Silver]

There will be a foot valve in the pump. Or a check close to it. If not every time the pump kicked out it would immediately lose system pressure and the pump would come back on again.
Does this water get cause much mineralization or is it pretty pure? Just thinking about that diaphragm in the pressure switch.

 

[Brute 23]

When the pump is running non-stop is the air comp?

If the comp is not but the pump is the pump is just cavitating as explained above until some thing gets opened and allows flow.

If comp and pump are running its definitely a external leak.

 

[simme]

I have no experience with an air lift pump system. I read that they are used to lift water with a lot of sand that would eat up a submerged pump mounted in the well. Could it be that the above ground tank has accumulated so much sand that it is restricting the capacity of the electric pump? Also that the lift capacity is dependent on the lower end being submerged about twice the distance from the water surface to the above ground tank. Is the water level in the well lower than normal giving less flow rate out of the well? I have never seen one of these systems. Let us know what you find.

 

[greybeard]

We have good water here. A little bit of iron ore I suppose but not enough to see, smell or taste.