Air bound water tank

[Ed Christie]

Some how the water tank loses the air in the tank. After a few months the well pump starts to short cycle. At this time I remove the plug that is about halfway up the tank and drain the excess water out.replace the plug and everything is OK for a few months more.

I can find no where for the air to leak out. It seems like it has to be at the top of the tank, above the plug that I remove to drain out the excess water. I don't think that it is the drain plug because as soon as it gets below the water level if there was any leak, it would then be water, and I dont see any wet spots.

Any Ideas would be appreciated.

Ed Christie

[Harry K]

If your tank is a bladderless, there is nothing wrong with it. The air isn't leaking out, it is being absorbed in the water. A few months is about the right time. You do have a problem with the snifter valve or other means that should be adding a shot of air every time the pump starts.

If it is a bladder tank, your bladder is broken.

The simple fix in both cases is to simply replace the tank with a bladder type. Cost of tank is reasonable and installation easy for average homeowner.

Harry K

[Stormin Mormon]

The one time I worked on someething like t his, there was a diaphragm gadget on the end of the tank. From what I could tell, it was deigned to inject a little bit of air into the tank every time the well pump turned on. Seemed like a good idea.

Wonder if you can replace that plug with a nipple and an air chuck (like on car tire) and then just inflate the tank a bit instead of draining it?

[David Efflandt]

You need more than a half tank of atmospheric air for the tank to function optimally. During normal operation it should be approximately 2/3rds full of air under pressure to be most effective. The air will expand to evacuate most of the water out of the tank about the pump kicks on, and compress as the pump reaches shutoff.

Assuming a bladderless tank or blown bladder, this means initially shutting off the pump, draining ALL water out of the tank, close water valve to tank and pump it up with air to about 5 psi less than the pressure switch turns the pump on.

But if a bladderless tank or blown bladder, the water will absorb air, so you need to recharge the air occasionally. There should be a Schrader valve (like on a tire) somewhere for that purpose if it was plumbed properly.

[Duane Bozarth]

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Every one I've ever seen has recommend precisely 2 lb differential (less, obviously) relative to the cut-on pressure.

[TURTLE]

This is Turtle.

If it is a Bladderless tank as it sounds to be 3 to 6 month time between draining to get the bladder area to fill with air is not out of normal times to have to do this. Now if you did get a rubber bladder tank for your use as the tank. It would be a long time between filling air again for the rubber bladder usely does not leak and last a long time. Now Bladderless is cheaper to have on cost to buy.

TURTLE

[Harry K]

I should have expanded that a bit. I recommend replacing with a bladder tank because that fixes the problem and eliminates having to air up your tank every few months. It also makes your system work closer to optimum, i.e., minimum number of pump starts. The bladder tank needs to be aired up to 2 psi below your cut-in pressure. The bladderless begins with the correct pressure when you first air it up then gradually goes off optimum untill you are short cycling again.

Harry K

[Backlash]

Anytime I have ever had this problem on a pump, a replacement of the air volume control on the tank took care of it. Quick and easy to do. One of my Myers pumps ran 23 years before it had a problem, then it was the air volume control. I think I got my money's worth on that one.

RJ