Troubleshooting well pump ( with pics)

[Mikepier]

OK here is another test I did. I have a Wayne portable pump. It is self priming, and hose bibs for the inlet and outlet. I stuck a 10 foot house down the well and sucked all the water out. The water did not return to it's steady state level until about 3-4 minutes later. Does this imply the screen is clogged , or there is a problem with the well? It seems there should be a steady supply of water if I'm sucking it out with my portable pump.

[Harry K]

Hmmm...that sounds like the 'recovery rate' of the well is too slow to be of use.

Back to your pump for a bit of clarification.

When you first fire it up, does it pump what looks like a normal flow and then go to a trickle? If it does, that is another clue that the well does not have sufficient in-flow to be of much use.

Harry K

[RBM]

That pretty much demonstrates that the foot valve is stuck, practically closed or clogged. Filling the pipe with water and seeing it slowly drain out shows the same thing

[Mikepier]

It seems to flow good at first for the first few seconds, then gets irratic.

[Tony]

How deep is the well? How far down does the original pipe go? Put the pipe down another 10 or 20 feet and see if it still goes dry. If it does, then go deeper. If you hit bottom, lift it up again so it doesn't suck up the sediment at the bottom.

[Harry K]

It also sounds like whoever installed all those checkvalves didn't know what he was doing.

Harry K

[Harry K]

True only if he stuck that hose down the suction pipe. I assumed (yes I know) that he had put it down beside it. If he did stick it down the suction pipe, you are right - footvalve problem.

Harry K

[dpb]

Well, that's what would be expected if the footvalve were mostly closed; empty the well pipe and then wait. Otoh, of course, it could also be indicative that the well recovery rate is slow enough that the only way for it to be usable is to have a large pressure tank and pump the well very, very slowly and use from the reservoir.

But, the above assumes the suction pipe is the one you're pumping out of rather than between it and the casing (again, assuming this is a cased well altho I'm now highly suspicious it is simply a driven sandpoint) rather than a drilled well given the depth and the description.

If that's the case, it'll be a bear to pull by hand because there is no casing; the pipe is in direct contact w/ the ground as it was simply driven. It also raises the probability that the well capacity is simply that slow refresh rate and won't be of much value for irrigation unless it's a very small area.

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[RBM]

True only if he stuck that hose down the suction pipe. I assumed (yes I know) that he had put it down beside it. If he did stick it down the suction pipe, you are right - footvalve problem.

Harry K

From his picture, it appears that there is only the one pipe

[Tony]

Here is says it should have a check valve every 200 feet. I could have been wrong about every 100 feet, mine may be every 200 or 100. I just know there are a lot more than the one at the pump and the one up top before the tank.

[[SMF]]

That's a different application. With centrifugal pumps a foot valve is used at the end of the siphon pipe, and a check valve is used post pump, if at all.

The foot valve keeps water in the pipe to aid priming of the pump, the check valve provides initial restriction to flow to prevent cavitation/introduction of air in impeller housing, and loss of prime at start up (Both input/output of impeller has water present).

Submersible pumps use checks valves at 200ft intervals to prevent excessive head pressure on the lower check valves (think of driving a wedge into a crevice with 10 pounds of force versus 50 pounds of force). Which option will be harder to get unstuck with a finite amount of pressure to get it unstuck?

[Tony]

Yes, at that point I realized I was talking about the wrong type of pump. Without a doubt I was wrong. I was replying to the comment

"> It also sounds like whoever installed all those checkvalves didn't > know what he was doing."

I assumed it was then realized I have a submersible pump, nothing like the OP's setup, being that it is 800 or so feet deep. I suppose I should not have assumed anything, after all, you know what they say....

[tnom]

You talk as if a foot valve is not a check valve?

[tnom]

A foot valve (check valve) adds the same restriction.

[Mikepier]

When the specs say the limit is "25 feet of head", does that mean the actual depth of the water level in the pipe cannot be more than 25 feet below the pump? Reason I ask is my water level is 2 feet below the basement floor, but the actual well casing is at least more than 30 feet down. I stuck an electrical snake down the casing, and it reached 30 feet until the end of the snake, so its probably even deeper.

[Mikepier]

I think I am going to rig up some kind of test. Fill a 5 gal bucket with water, stick a suction pipe in the bucket, and see if this pump works. If it does, then I know it must be the well.

[krw]

No, the "head" is how far it will pump vertically, above the pump. That doesn't mean that your pump can't lift water from 25 feet down (though that would be about the limit for any pump). "Shallow well" or "jet" pumps are designed to lift water from wells lower than the pump. "Deep well" pumps are put down in the well and can lift higher.

The level of the well casing doesn't matter, only the level of the water. Of course the level will go down when the pump is operating and further in dry times.

[Harry K]

A foot valve is a check valve, yes. But what the others asre talking about are clearly _not_ footvalves. If they meant a footvalve they would use the proper term.

I see this all the time here, the instant a pump problem is mentioned the swarm of "check valve" shows up - a clear indication that the posters are probably not knowledgable about pump systems.

Harry K

[Harry K]

And the point is that adding another, useless, unneccessary one at the top causes _more_ restriction. One is all that is needed in the system and one in workign order is absolutely necessary. Of course if the pump is self-priming and within about 26 ft fromt he static water level the footvalve can be eliminated.

There is an exception. In the case of a submerged pump (they contain a checkvalve internally) where that valve is leaking back, one can 'shadetree' a fix by inserting a checkvalve up top prior to the pressure tank. Keeps the sytem from draining back when the pump shuts down.

The reason that doesn't work on suction pumps is that the intake pipe must be kept full of water to maintain prime. Unless, of course, the pump is self priming and is no more that about 26ft above the static water level.

Harry K

[Harry K]

Yes, measured from pump to the top of the water. Matter of physics, water can be sucked up a pipe only by air pressure pushign down on it. Theoretically atmospheric air pressure at around 14 psi would allow 'sucking' up to 34 ft but restrictions to flow, etc cut that down to the accepted figure of 25-26 ft.

Even at 2ft, without a check valve your pump must be self priming.

After thinking over the problem I can ony think of 3 items that may be the problem.

1. Malfunctioning foot valve
2. Pump worn out - probably not as it appears it pumps out the prime just fine.
3. Well not producing enought water to maintain flow - probably not in your case. If the well has 20 ft of water in the cased portion it would take more than a very short period to pump it 'dry'.

Looks like footvalve to me.

Question: What is the 'cased size' of the well? Wide enough to put a new suction ipe in alongside the one already there? If so, that is what I would do if it is physically possible.

Harry K Harry K

Harry K