Water Tank Air FAQs
Questions & answers about the air charge in a water pressure tank

  • WATER TANK AIR LOSS FAQs - CONTENTS: questions & answers about the air charge in a water pressure tank help in diagnosing & correcting a waterlogged water pressure tank and other water quantity or flow or pressure problems.
  • POST a QUESTION or READ FAQs on a water pressure tank has become water-logged or has lost its air charge
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Water tank air charge questions & answers:

This article answers questions about problems with the air charge in a water pressure tank. Too much air, not enough air, air loss, air discharge at faucets, and pump short cycling all can be related to the air charge in a water tank.

This article series describes how to diagnose the loss of and need for air in a water tank, how to add air to a building water pressure tank, and how to detect and correct air and water leaks in a building water supply system where a private well is the water source. We also discuss how to adjust the building water pressure by setting the cut-in and cut-out pressure on the pump pressure control switch.

Green links show where you are. © Copyright 2017, All Rights Reserved.

FAQs about the proper charge of air in a water tank

Waterlogged water pressure tank schematic (C) Carson Dunlop Associates

Question: How long is the normal on/off cycle for a water pump?

(Aug 1, 2014) Bai said:
How long is the normal on/off cycle for a water pump? We recently replaced our water pump because the old unit got stolen. Because of this,we made a new well and relocated our pump. The one installed now takes too much time to fill up the tank. Here's our set up for the new well:

1) 7 2" GI Pipe for well casing
2) 4 1 1/4" GI Pipe with 1 1/4" foot valve dropped inside the casing
3) 1 1/4" GI Pipe runs into the pump and out a 1 1/4" pipe through 2 82 gallon tanks

It really takes a long time for the tank to fill up to 30 PSI. It takes a longer time to fill up when the pressure hits 20 PSI. I'm afraid we could burn the motor if we continue this.

[Click to enlarge any image]

Images of the operation of a waterlogged pressure tank shown here are provided courtesy of Carson Dunlop Associates, a Toronto home inspection & education company, used with permission.

Also see the diagnostic guide starting at WATER PRESSURE LOSS DIAGNOSIS & REPAIR or select a topic from the More Reading links or topic ARTICLE INDEX at the end of this article.


The short answer is the fill time depends on the tank size, pump rate and well flow rate. We gave a longer answer at the other page where you posted this question.

Question: How do you tell if your pressure tank needs more air?

(Sept 3, 2014) Anonymous said:
How do you tell if your pressure tank needs more air?



Question: Do I have to drain my water tank prior to adding air?

Oct 6, 2014) George said:
Do I have to drain my tank prior to adding air? My air pres. is now at 26PSI and it is suggested I increase to 38PSI


No George, but 38 psi sounds a bit high unless the pump control cut-in pressure is 40 psi - which would be odd and high.

Question: pump never gets to shutoff pressure until I turn off the shower - is this a water tank problem?

(Nov 6, 2014) Brad Shoults said:
I have my pressure switch set at 20 psi on 50 psi off. everything was fine, but now I notice with just a shower running the pump can't get up to shut off pressure and never quits till shower is off. Too much water in tank, bad impeller,any suggestions?



I'd look for

- something else is running water
- a leak in well piping
- a reduction in well flow rate
- a bad pump impeller
- a dirty water filter

I don't think a waterlogged tank can cause the problem you describe

Question: pump pressure switch setting creep?

(Mar 24, 2015) Bob Chervenock said:
Pump pressure switch was set to 30psi on and 50psi off. Over time, pressure gauge now has risen to 40psi on and 58psi off. Is bladder tank low on air or is pressure switch out of adjustment?


I don't often see creep in the pressure switch itself.

Check for a gauge that's sticking - make an independent pressure measurement.

If pressure is creeping up and you re-set the switch and it still creeps up I suspect there might be a pinhole leak in the bladder - if your system uses a bladder type tank.

Question: air and water spurts out of faucets

(Sept 27, 2015) ken said:
air builds up in piping and comming out of faucet. Water spurts out at times, or high air is released under higher pressure.



Search InspectApedia for "AIR DISCHARGE FROM FAUCETS" to read diagnostic and repair suggestions for the condition you describe.

Question: loud THUD and SPROING noise from water system

(Mar 8, 2016) yvonne said:
city girl moved to country. newbie with well water systems. woken this morning at 4am by a large - like SUPER LOUD - "SPROING" noise. yes, that cartoon noise like a big coiled spring releasing. and at the same time a loud THUD.
I went downstairs, and checked the basement out, not knowing what it could have been, and now i am wondering if there is something going on with the well pump/tank. and now sitting here typing this, i remember about 2 weeks ago, my boyfriend said he heard that noise too, once. I have checked this site out, but see nothing even similar to it regarding issues/symptoms. any ideas?

I should add to my comment below, that no water has been turned on or off at the time.
there was no one else in the house at the time, and no automatic sprinklers or anything.


Yvonne, I'd like to help out with SPROING and THUD noises but geez, seems as if lots of things can go SPROING, THUD. If you heard these noises at the water tank and pump controls perhaps we're hearing a water hammer noise associated with a pump turning on or off. In any event loud sporinghtud sounds are ominous, as if some component is in trouble.

See if you can pin down the sounds to

- the room or building area indoors or outside
- the specific equipment
- the turning on or off of equipment, faucets, switches, of any sort.

Also search InspectApedia for WATER PRESSURE SWITCH NOISE and for WATER HAMMER NOISE to read more diagnostic suggestions.

keep me posted

Question: pressure drops when pump kicks on, jumpy pressure needle

Apr 19, 2016) JeffB said:
I have typical water well with pressure tank. I've had pretty low water pressure in upstairs for quite some time. In attempt to improve things, I adjusted the tank so it clicks on at 30 and clicks off at 50. I also pumped air in the tank to bring it up to 28 pounds. It seemed to improve things for about a week, but now things are worse than they were before. I noticed a few symptoms that I thought might help someone with experience diagnose my issue:
- when the pressure reaches its cut off point, the pump shuts off. The pressure drops somewhere between 5 and 10 pounds before it stabilizes.
- I notice that the pressure needle is quite jumpy when it reaches the cut-on point too.
- when the pressure tank is filling, the *rate* at which the pressure climbs also goes up
- when the water pump kicks off, the tubing that goes to the pump shakes back and forth significantly and makes a noise that can be heard upstairs

Any ideas? Thanks in advance!



I am guessing that your pump is having trouble reaching the 50 psi cutout. Try dropping it to 45 and let me know if that helps. You'll have higher pressure but more frequent pump on-off cycles (causing pump wear). I'm also guessing that the pump has been damaged by running dry or in low water in a low recovery-rate well.

(Apr 19, 2016) JeffB said:
Dan.. thanks for the quick response. I would think if that were the problem, then the pump would work a lot longer before shutting off? It only runs for about a minute before cutting off. Unlike another property that we owned, this house always seems to have a well that produces a lot of water. IDK.

Anonymous said:
Jeff if a pump consistently runs for just a short time after you've turned off any running water that suggests the pressure tank is waterlogged

Question: pinhole leaks in copper piping

(May 2, 2016) JJ said:
Hi. We just replaced some corroded pipe that comes out of the pressure tank (our copper piping tends to pinhole in this house, so re replaced the no-good bit with a piece of pex, put in a new shutoff valve, and fastened the whole thing back together). Since the pressure tank was drained and refilled during the course of this work the pump is short-cycling a lot! We were going to try to test the bladder and see if it has proper pressure in it, but now i'm wondering if somehow we ended up with extra air trapped inside the tank when we refilled it and it didn't come out through the pipes.

ALSO almost 2 weeks on, a new leak started - out a spigot on the set of piping that contains the pressure switch & house exit line. it's a spigot with no shutoff, and I've no idea what to do about that.
any thoughts on either issue? and might they be related? is our best starting point to test the pressure of the air bladder and go from there? thanks so much!



About pinholes in copper piping: have your water tested for corrosivity. It may need to be treated.

If your water tank uses an internal bladder, the water and air are kept separate. Only if the bladder is burst or damaged would water (or air) move from the water pump and piping into the tank body.

Question: no water pressure

(May 9, 2016) Ginger said:
We an no longer water the yard and run water anywhere in home



If you mean that you have no water anywhere search for NO WATER PRESSURE to read an organized approach to diagnosis and repair of this problem.

If you mean you have water indoors but not at your outside faucets, then most likely a shutoff valve has become closed or a faucet or pipe or elbow clogged.

Question: water pump cycles quickly and continuously

(May 26, 2016) Kelly said:
I replaced our pressure tank because the old one started leaking and the pump short cycles very rapidly and continuously. I replaced the pressure switch thinking that was the issue and the new switch is kicking in and out the same way. We cannot use the system as it is so I need to find a solution. The contractor charges $125./hr and I cannot afford them.


Please search for WATER PUMP SHORT CYCLING to see how to diagnose and fix the problem.

Question: how much air pressure needed in my tank?

(May 29, 2016) Anonymous said:
How mush air pressure is neede in my tank?


Anon, in the ARTICLE INDEX or related links above, just below the Continue Reading link above, click on


Question: pump kicks on for 6 seconds

(June 5, 2016) Lisa said:
My tank is at least 20 y/o. My pump is kicking in for 6 seconds, shuts off and kicks on after a few minutes while water is running. If the water isn't running, it kicks on about every half hour. It's a bladder tank. I've checked for leaks and found no water leaks in any of the pipes or faucets. The points are only a couple of years old. Should I replace my tank?


Check for a dirty water filter or other pump or tank outlet blockage, and check that water is entering the bladder in the tank: you should see the pressure climb when the pump first starts. I wouldn't replace the tank unless investigation shows that the water tank bladder has burst. Search InspectApedia for WATER TANK BLADDER BURST to read more.

(June 5, 2016) Lisa said:
It doesn't show that is losing pressure or gaining pressure when it kicks on. There is no drop in pressure when the water is running. I've done the turn of the power, drain the tank and then refill it thing. But, there is constant moisture on the slab around the tank with no leaks in the pipes going in or out of the tank.

(mod) said:
That suggests that the gauge is not working, stuck, debris-clogged or something similar.

Moisture around a water tank can be simply from condensation dripping off of the tank; but if can inspect the tank under-side (without moving pipes and causing worse trouble) double check that there's no damage there.

(June 5, 2016) Lisa said:
Thanks for the advice! I'm get my son to come over and help me! You're a Godsend!

(mod) said:
Glad to assist; keep us posted: working together helps us all.

Question: pump runs if I give the tank a little shake

(June 15, 2016) Matt said:
My water in my house stops working. If I go down to the tank and give it a little shake, my water starts working again for a short period of time. Could this be air pressure or maybe a switch?
flag like


Sounds like a loose connection or switch component. Next time try tapping on the pressure control switch. Debris can clog its sensor. If so replace the switch. Keep me posted, Matt.

Question: converting back from city water to well water, now water pressure is erratic

2016 09 03 Matt said:

We recently bought a house in a rural community that was hooked up to city water. After a few months of paying enormous water bills I decided that paying the city for what I have in the back yard was ludicuris. So, I go out and turn the power on to the well and low and behold it worked like magic. The tank and preasure switch were a bit dusty but over all everything looked good. And it worked. so a buddy of mine and I dug up the back yard, found the pipes from the well to the house, inspected them and hooked them back up to the house. Everything worked fine for a couple of weeks then the water preasure became quite Eratic.

The water out of the faucets would flow like...water water WATER water water WATER WATER water water.. I'm new to this and have read a bit here. I pretty much decided to start with the preasure switch since it took a couple of flips to get it working. Any other ideas for me to look in to?


Erratic water pressure?

My first concern would be safe drinking water. Don't drink unknown water without first having at the very least a potability test.

Next, you want to be darn sure that your private well cannot accidentally back-feed your well water into the municipal system. You should never be connected to both systems at the same time, and a mere shutoff valve between them won't satisfy your health department (as someone could leave the valve open) - disconnect from city water completely if you're going back to using your well.

My next thought is that if someone went to the expense and trouble to connect to city water it was probably because they were finding the well inadequate. Sure the well itself could have been OK and the problem could have been with pump, control, piping, valves that get mis-diagnosed.

You may have seen what looked like plenty of water while you were drawing only water that was in the well bore itself - the static head. Once you exhaust that water if your usage rate exceeds the well flow rate of water into the well bore, you'll run out of water. Your pump may include a protection circuit or switch that shuts it off when it's not pulling water - lest the pump itself be ruined.

Search for WELL FLOW TEST to see how to find out what the well can deliver.

Search for WATER QUALITY TEST to see more about testing the water for potability - is it safe to drink?


Continue reading at WATER TANK AIR LOSS SIGNS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES. or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see AIR VOLUME CONTROLS, WATER TANK used on bladderless water pressure tanks





Suggested citation for this web page

WATER TANK AIR LOSS FAQs at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Questions & answers on how to determine that a water pressure tank has become water-logged or has lost its air charge

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman