We're getting a lot of air in our water supply from a private well. This seems to coincide with a change made to the well. Here are the details:

1. About 2 years ago, the well casing was shortened by about 3 feet, the pitless adapter was moved down the same 3 feet, and pump was lowered 3 feet. No length was taken off the pipe running from the pitless to the well pump. Well is about 80 feet deep.

2. I recently cut the main water line (from the well) to install a filter before the pressure tank. I thought I had the well pump turned off but didn't. Surprisingly, there was no water in the well line. After purging the main line of air, the house fixtures operated for about 2 days without any air in the lines, then it returned.

3. Today, I used the pressure purge valve on top of the filter to see if there was any air in it... nothing happened - no air or water came out... so I can assume that, as before, the water is filling the pressure tank and then backs out of the pipe - I'm guessing towards the well but don't know if it backs out all the way to the well as the response time to refill the pressure tank is pretty fast. When the well pump is running, the water filter will purge air at first and then puts out a steady stream of water.

4. When the well runs, there is a ton of water flow with no apparent air in the line - I get this from just observing the disconnected well line and the pump running.

So, it seems to me that there's a failed check valve that's causing the water to back up in the line until it's called for again. Or is this supposed to happen? Or is the pump sucking air as a result of having been lowered 3 feet? That doesn't make sense to me but I'm no expert on this...

Any help or testing ideas would be appreciated. Thanks!

What kind of pump are we dealing with, a submersible pump (in the well) or jet pump (above ground)? If it's a jet pump, then a leak in the suction line will allow air into the system.

A faulty check valve will show up by allowing your pressure tank to empty back into the well when no water is being used in the system. You can notice this by watching the pressure fall on the pressure gauge. It is possible that the filter you installed (which is typically placed after the pressure tank, not before it) is leaking enough air to allow air in the line. When the pump cuts back in, this air will either go into your tank or simply flow through into the house.

Thanks for the fast reply... this is a submerisble pump. Yes, there is a check valve - a brass valve labeled "200lbs" is installed on the main well water line just prior to the pressure tank. Consequently, the pressure gauge won't change even though the water is emptying from the main line back towards the well.

I went back out and listened to it a few minutes ago... the pump kicks on when the pressure on the house-side of the check valve hits about 35psi, the pump runs for 30 seconds and shuts off when the same gauge reads 38psi.

When the well pump shuts off, I can hear the water flowing out the main line towards the well - this explains why the line was empty when I cut it. This sounds like the pump has a failed check valve (if it has one) or perhaps there is a failed check valve in the well itself - I should be able to hear the water rushing into the well if either is true... pulling the pump will be interesting depending upon the type of line used on it... I don't recall there being a safety line attached.

I don't think this can be a break in the line from the house to the well as it would have to be a very large break which would greatly affect the water volume which seemed to be strong.

Is my thinking correct?

For water to go back into the well, I would first suspect the check valve next to the tank. Even if the lower valves were leaking, that would not allow air into the well pipe... it would draw a partial vacuum. For air to be in the line, there has to be a leak somewhere to allow air in.

Your pump should not be cutting off only 3# above the cut in pressure of 35#. Something is wrong there with your switch. I would suggest you pull the switch off and check the little pipe leading to the switch.

MOre later. I have to go to work!

Here's what I found out a few minutes ago:

... pulled the well cover... haven't run the pump in 10 hours... I can hear lots of water running in the well... we had a lot of rain the past few weeks...

When I turn the pump on I can definitely hear a sucking of air which appears to be coming from the pitless adapter or close to it. The pump is about 80 feet below the pitless. When the pump is turned off I can also hear air escaping (?)...

There's no water escaping at the pitless when the pump is running or when off... shouldn't water escape also at the pitless once the line is full of water if there is an air leak at that point? And shouldn't water leak out of the pitless thereby creating the void in the main line?

Why do you suspect the check valve at the tank? It seems to be working by not letting the water drain back to the well from the other side of that valve (the house side)... there is no schrader valve on the check valve to permit it to take in air.
Confused...

I would look at the checkvalve nearest the tank in hopes that it would be the culprit. Reason: price. Easy to replace.

If your pitless adapter is leaking air, then you have probably found your problem. Probably time to call in a well pro for that.

You still need to address to problem of your pump only pumping up from 35# to 38#. You should have about a 20# interval, not a 3#.

Thanks... I don't think it can be the check valve at the tank as the line doesn't lose pressure on the house side... in other words, the check valve is stopping the water where it should... its the well side of that valve where the water retreats... or am I not understanding your point?

I bought a pressure gauge tonight to replace the existing one. So you're saying the main water line at the air tank should go from 40psi to 20psi and then back up again when the line is represurized by the pump? You're not talking about the 20lb swing occurring in the tank are you?

I also bought one inch pipe to pull the pump up and examine the pitless... I can't imagine it's that difficult to replace the pitless if I need to... I've already excavated the outside of the well casing and confirmed no air leaks at the pitless exterior...

I went back out and listened to it a few minutes ago...the pump kicks on when the pressure on the house-side of the check valve hits about 35psi, the pump runs for 30 seconds and shuts off when the same gauge reads 38psi.

That is what I am referring to. If your pump cuts on at 35, then it should pump up to around 55 before it cuts off. You don't want your pump cycling for thirty seconds. The reason is that the pump works very hard the first second or two it cuts on. Short cycles wear pumps out prematurely. I would suggest you remove the switch (small grey box with wires coming in/out) by unscrewing it from the small pipe which connects it to the system. Oftentimes these pipes become clogged with crud. If it's not clogged, then a new switch is probably in order.

I can't comment much on a pitless adapter. I'm in the south. We have, basically, no real frost line so pitless adapters are but rarely used. We simply use a pumphouse.

Scuba, do let us know how this pans out. You have one of those interesting posts that can expand the knowledge base of all of us. The good news is that pitless adapters are not wildly expensive, less than $100.00 is many cases. If you are going to do the work yourself, then you are the kind of "wildman" we need more of. Best of luck.

BTW, yes, the pressure is in the tank. In fact, that is the purpose of the tank. MOst new switches are preset at 20/40 or 30/50, but that can be adjusted. Good news... they are cheap to purchase unless you go digital.

Ok... pulled the pump up enough to view the pitless connection on the pipe... the pitless O-ring has a nick in it which is probably causing the air leak... not too hard to pull up but the pipe is full of water which adds a lot to the difficulty... I'll buy a new o-ring and see if that fixes it.

Thanks for the tips on the tank...

You probably plan on doing this, but be sure to check your checkvalve above the pump. That would seem to be the one leaking.

OK... couldn't find an o - ring to match... so I reversed the existing one, that didn't appear to work... went to pull the pump... got about 15 feet out of the casing when I came across a plastic connector of some kind... about 1.5 inches round and about 2 inches tall... water was leaking out of a triangular shaped hole in the side of it... very strange... anybody know what this could be? About 8 feet below the pitless... could this be the air leak?

Thunder and rain forced me to stop...

Can you put up a picture of it? Sounds like a check valve due to the size. Is it threaded?

Here is a picture of the part I was referring to... what is this? I think it was leaking water where the arrow is pointing...





The pump is about 40 feet below this point I think...

I've never seen one like it, but it would have to be a check valve. I say that because I cannot imagine what else it could be. It would seem to be in the wrong place. A check valve is generally placed 10' or so above the pump and then between the pressure tank and the wellhead. One good thing... you can take this thing out, put the pump back in, and see if the problem is solved.

If the pump cycles for 30 seconds suspect a water logged pressure tank first. If it is a bladder tank the bladder may be ruptured. Turn off pump and shut off pipe to house. Drain the pressure tank all the way. I hope you have a hose bib there on the "tank tee" to do it. Close up and turn the pump back on. See how long it takes to re pressurize the tank. If it's only 30 seconds there is a different problem, maybe with the pressure switch. If it takes maybe two minutes to pump up you've found your problem. The system was water logged. Using that drain procedure once a month you can keep limping along, but best to replace the pressure tank soon. I should also say that when the tank is empty and the pump is off use a tire gauge to measure pressure in the bladder at the tire fitting on the top of the pressure tank. If it has pressure, say 20 psi, when the tank is empty, the bladder is still good. Look elsewhere for the problem.

Great answer but a little late. We look forward to seeing more of you on The Plumbing Page. Regards, Tom