When the water isn't used in a while, my tank will bang when drawing water. If it's in use and draws water it just clicks as it should.

By "water tank" are you talking about a hot water heater or a pressure/bladder tank on a pump? Back to you, Tom

Even as I am not a veteran in plumbing, on the basis of my own experience, I can say that there can be some trash in there that's vibrating as the water rushes past. See if you can flush it out. Does it help?

Hello Wupper,

Please respond to TOM.

If it is a water heater then I agree with Kahani Punja, Try to flush your water heater it may help, if you need help how to flush come back and we will tell how, Thanks.

John

It is a water tank. We are in a rural area.
It's a 40 gallon bladder tank.

Another question. How do I respond to TOM?
You just have. In the future please simply click on the "edit" button and don't start a new thread. Tom

I have a new question.
I have an 82 gallon Flotec water tank served by a well pump.
My tank bangs when pulling water.
I've adjusted the air pressure as recommended.
The question is, when I tap on my tank from top to bottom it sounds empty.Is it?
My gauge will come on at 38 LBS and go off at 60.
My cycle when using constant water is about 10 minutes. Is this too quick?
The bang doesn't happen when we are using water a lot. Only when it sits awhile.

If you pop the tire valve on top and get water you have a ruptured bladder but it really doesn't sound like it. What's the tanks PSI. It should set at 36 PSI with the pump off and a cold water faucet opened to bleed off the pressure. I that the setting that you have?
Your cycle will depend on how much volume you make on your draw, ( how many GPM)

my tank will bang when drawing water. If it's in use and draws water it just clicks as it should. Describe the bang. Loud? Does the tank vibrate? And what clicks? The tank? I'm going to put up a image of bladder tank operation. There should be nothing in the tank to either bang or click. Regards, Tom

No water at all from the valve.
I have it set at 38lbs, but have set it at 36, 34, 32, with no change. Still the same.
The tank bangs and everything vibrates, pipes, etc.
Loud? Yes, startling!
The click happens when it reaches the 60lbs pressure.
Again, the empty sound when I tap the sides, and I can move the tank easily. That makes me think there is no water in it, but how can that be?
I'm getting the pressure in the house water taps.
Is it possible that I have a bad o-ring on the pitless adapter? Someone suggested this.

The click is normal. That's the switch cutting your pump off. There should also be a click when the pressure gets down to thirty eight pounds and the pump cuts on.

How did we go from a 40 gallon tank to an 82 gallon tank? Is this happening with two separate systems?

Is your pump above ground or in the well?

Sorry, the tank is 82 gallons. (My mistake)
The click that is supposed to happen at 38 pounds (when the pump cuts on)is when the loud bang happens.
The pump is in the well.

I thought the "click" was in the tank but jlisenbe gives a pleasable explanation.
About the only way a bladder tank would be empty when the pump shuts down at 60PSI is if the tank setting exceeded 60PSI or the membrane has become se stiff that it's no longer flexable. But I just had a thought, ( I get them once a day). If there were a pebble or small rock blocking the bladder tank inlet The pressure would force in against stopping the water from entering and resulting in a thump or bang. I realize that this is "out there" but it's the best I can come up with. It's worth looking in to. Does the pump kick on every time you make a draw? What's a "pittless adapter ? Is your pump located above grown or in the well? And what does this "pittless adapter" have to do with the bladder tank? Back to you, Tom

Tom, yes, it draws like it's supposed to, but it bangs (as if air is in the line) when it hasn't drawn for a while. When it's running a lot,(washing clothes, showering, etc) it doesn't bang when it draws.

Have you shut the pump down and removed the bladder tank? Something's not right and it all points back to the tank. With the tank removed turn the pump on for a second. Did water shoot up out of the tee? What's a "pittless adapter ? Is your pump located above grown or in the well? And what does this "pittless adapter" have to do with the bladder tank? Let me know, Tom

Tom, a pitless adaptor is the connection between the house hose and the well hose. There is an O ring that goes on at the "tee"
I had two suggestions from friends, not plumbers.
One said the o ring could be bad, therefore letting in air (thus, the banging) and the other friend said my gate valve at the well might be bad.(Again, allowing the well hose to empty, therefore allowing air to come before the water when it draws water.
I'm hoping I don't have to pull the well pump.

Wup, two thoughts.

This only happens when the pump has been sitting for a while. And, your 80 gallon tank seems to be mostly empty. So, I'm going to guess you have a leaking check valve. This allows water to drop down the well pipe. It's slow, so it doesn't happen enough to matter much until there is a long period when no water is used.

When the pump cuts on, there is a partial vacuum in your wellpipe. This allows the water column to really bang into your pressure tank.

If that is the case, then putting a checkvalve just before your tank would be a possible fix.

jlisenbe,
As I feared, this does seem to be the problem.
I do have a check valve right before the tank so this stops the water from leaching out of the tank, but the hose to the well empties and creates the air pocket.
I guess I'll have to pull up the well pump. Thanks all for your input.

NOt sure about your setup, but why not simply replace the CV? Should be fairly simple.

That's what I think I have to do, but the check valve is on the pump in the well.
I've already changed the check valve right before the tank but that didn't work.

I think you are on the right track. Some well pros suggest multiple CVs for this very reason. With a partial vacuum under the top CV, the pump kicking on sends a column of water up the wellpipe and it "slaps" the upper CV. That is probably what you are hearing. When the pump has to kick on frequently, there is not enough time for the water column to drain down enough to make much difference. At least that's my thinking on it.

Please do let us know how this gets resolved.

OK Problem solved.
The check valve on the pump was bad. We installed a new check valve right before the pump because the original one was built into the pump and we didn't want to get involved tearing the pump apart.
Works like a charm.

Thanks so much for the update. Tom