I have an old (30 yr?) bladderless pressure tank on a shared (4 houses)
well. It appears that over the last six months, air has been entering
the tank somehow and ending up in the house water lines. I've been
bleeding air out of the tank about once every week to ten days and that
corrects the problem temporarily. My question is: is there any way (such
as a particular pump failure mode) that would allow this to be
happening, or is the only thing that could be wrong is that we are
pumping the well faster than it can recover? (There's no obvious reason
to think the water table has dropped in the last year.)
When I lived in New Hampshire (The Granite State), there was a process
called "hydro-fracting" which involved dropping dry ice down the well
shock cooling the bedrock and opening up the fissures to allow faster
well recovery. I now live in Northern British Columbia (on probably clay
and gravel), so my second question is: if we are overpumping the well,
what can be done about it?
Thanks a lot for any information.
Nope. If he has a jet pump or a shallow well one on top of the well
and the check valve (footvalve) was bad, he would be loosing the prime.
If it is a submersible, it pumps from under the water level and thus
can't suck air from there. The only place I can see air entering the
system at the pump location is from the snifter valve or a flapper
valve on the side of the tank. Dissolved gases in the well water??
There's definitely nothing on the side of the pressure tank and no
obvious places (clamps, etc.) where air could be leaking in. I suppose
the drop line may be cracked, which would reinforce some suspicion that
the problem coincided with the onset of cold weather--metal contracting
and opening up the crack.
My best guess is that it's a submersible pump in a deep well (The story
is that the original owner paid CA$10,000.00 in the '70's to have it
drilled--but there's some speculation he may have inflated that figure
to rip off the people he was going to share the well with. Nice guy.) As
I said before, I wouldn't be surprised if this is a real "half-fast"
system, just surprised it's lasted this long.
If you don't have a pump above ground, and you have wires going down the
well, then you have a submersible pump. Most likely the check valve is
threaded to it.
It's possible that the vertical pipe is cracked, but not probable. It would
be spraying water out the crack when the pump is running. Can you look down
the well and check that?
It's more likely that you have a crack or pin hole in a section of pipe that
It cannot be 'sucking' air in any section of pipe between the pump and
the tank. That is all pressurized and any leak is going to spray out,
not suck in. Same goes for any pipe on the delivery side of the tank.
The only way air can be sucked into a system is from before the pump.
My guess still remains as outgassing from the water or malfunctioning
snifter/float valve in the tank.
Sorta OT. I was on a community well (originally 4 houses), It was
down to 2 when I bought and somehow I wound up being an unpaid
serviceman for the system. Got tired of that and drilled my own well.
I have known others on community ones also and seems like all of them
Good point. I overlooked that the OP does have such a set-up. I
really don't understand why it is done since it is redundant other than
in one circumstance. A failure of the checkvalve at the pump, install
one at the tank to obviate pulling the pump. Of course that does
result in air in the pipes problems.
The check valve at the tank is so that house pressure does not put pressure
on the well system when the pump is off. The check valve at the pump is to
keep water in the well piping so you don't pump air every time the pump
If you say so. I see no need to worry about "pressure in the well
piping". There are a lot more items in the residence that will fail
from pressure before anything in the well will. I have never seen a
system with both check valves and have never worked on such a system
which is why I overlooked to two valves.
could be a bad check valve at the pump. when the pump is in the off
cycle it will allow the water to drain back.the check valve at the tank
will hold and the suction will allow air to be drawn in at the pitless
adapter o ring . when the pump cuts on it will push any air that has
entered into the tank. this is a very common problem with older systems
that have a check valve at the tank.be carefull if you are going to
attempt to pull the pump yourself as they can be very heavy in excess
of 300 pounds. we have to retrive many pumps that customers have
dropped. the cost of getting one out of a well that has fallen a
100-300 feet down the pipe will be greater than the repair would have
been in the first place. the last one we did fell 325 feet and cost
1800 to retrive and another 1400 to replace the pump. but it was still
cheaper than 10,500 for a new 1100 ft well. thanks and good luck. scott
That all makes sense except that I'm not sure this system has a pitless
adapter (is that possible?) The water line comes vertically out the top
of the well casing then through a ninety-deg elbow, through a
checkvalve, then a couple more nineties, a stop valve, then to the
pressure tank, etc. If there is a pitless in the system, can air really
pass the o-ring? I think this is as simple (i.e. cheap) a system as was
available in the '70's judging from the way the rest of the house was
built. Thanks again for your help.
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