Water pressure tank air pre-charge adjustment questions and answers.

This article series describes how to add air to a building water pressure tank and it reviews the function and repair of water tank air volume controls or snifter valves in a building water supply system where a private well is the water source.

The illustration at page top is courtesy of Carson Dunlop Associates, Inc. in Toronto.

FAQs: How to Add Air to a Water Tank

These questions and answers about why we need an air charge in a water pressure tank and how that air pressure is set and maintained were posted originally at WATER TANK AIR, HOW TO ADD - be sure to review the diagnosis and repair advice given there.

On 2018-11-27 by (mod) - signs that the tank bladder is stuck to itself

If your tank is a type that uses an internal bladder I suspect that the bladder is stuck to itself and water is not entering the tank. It may be possible to unstick the bladder or to replace it otherwise you would need a new tank.

On 2018-11-27 by Brian - short cycling pump, water does not enter the pressrue tank

QUESTION: My well pressure tank is short cycling - cutting in at 40psi and cutting out at 60psi - every 3-5 seconds when water is running in the house.

The tank is very light and feels like there is almost no water inside the tank. Is there any way to increase the water level inside the tank so the pump doesn't have to turn on so frequently?

Or anyway to check to see why the tank is not holding water?

The pump is underground and I have no access to check to see if the filter is clogged. The water pressure seems to be OK when running so I have to assume water is pumping into the tank OK.

On 2018-07-09 by Heather

Hello, my well pump was short cycling so I followed instructions on how to drain and refill the tank. The pump is no longer short cycling but I believe the water level in my tank is still too high. It is a galvanized tank without an AVC and I am concerned of an air leak somewhere. How do I know if there is enough air in the tank before it starts to short cycle again? thanks for all the information!

On 2018-04-08 by (mod) -

Thanks for the nice feed-back Richard. Working together makes us smarter.

On 2018-04-08 by Richard

Thanks for the pointers. I'm a novice when it comes to well water systems. Turns out my bladder tank had lost its charge. Between your hints and the instructions on the tank, I got it. Thanks again.

On 2017-07-06 by (mod) -

I suspect a bad check valve or water leaking into the ejector pit.

Use the search box just above to find our article on SEWAGE EJECTOR PUMPS to read details.

On 2017-07-03 by Ejector Pump runs every 15 sec

My ejector pump is running every 15 sec for about 3-5 seconds. There is hardly any water in the pit and no water is being added to set off the pump. The float is about 1 foot above the water line. Any suggestions?

On 2017-05-08 by (mod) - water tank won't hold pressure

Nancy

I'm puzzled by the situation too. Possibly moving the pump has moved a well pipe that in turn moved a connector that is allowing air to leak into the suction line of at two line jet pump system (if that's what you have).

On 2017-05-08 6 by Nancy

@Nancy,
I moved my blue tank slightly because it shifted off the bricks I had it on. the water pump was fine before that. now it will not hold the pressure and keeps going on and off

I moved my blue tank slightly because it shifted off the bricks I had it on. the pump and water were fine before that. then after that the guage would drop from 80 from to 60. when I run the water the pump goes on and off very quickly it sounds like air in the line

On 2016-02-09 1 by (mod) -

David I'm not sure I understand the problem nor the question, but I'd start by confirming the presence of water, then pulling the pump to check that it is undamaged.

Start with the diagnostics at WATER PUMP SHORT CYCLING - home

On 2016-02-09 by david

I have a cestern with a slimline pump new pressure tank my pump runs and off and right back on no watter running no where

On 2016-02-07 by (mod) - how to restore air charge in a buried water pressure tank

Sounds like your water tank is waterlogged. .. no air

Larry

Because buried water tanks with no physical access are very unusual we have not found specifications, photos, history, procedures.

You may be able to force air into the tank by backpumping air through the water supply line exiting the tank, after installing a suitable fitting, valve, and Schrader valve.

But if the tank's water line exits at the top of the tank it'd be impossible to keep air in the tank itself.

On 2016-02-07 by Larry L

There is nothing about adding air to an underground tank that is saturated. Cant put pressure into the tank from Schrader valve. Constant short cycle. Can't vacuum water out of tank from shop vac.Why hardly info on underground tanks?

On 2016-02-07 by Patrick k

My water pump is short cycling whenever I use the faucets or shower, when I try to check the air pressure on top of the tank via the valve stem, water spurts out when I attatch the pressure gauge

On 2016-01-18 y Philip

The motor on the water pump is just becoming hot but not pumping water into the plumbing system. The usual noise isn't coming at all. What could be the problem?

On 2015-11-14 by (mod) - house water supply can't keep up with demand

Let's separate 2 issues. Losing prime is a foot valve or leak problem.

Short cycling pump is a waterlogged pressure tank problem.

An internal bladder type tank will improve the second issue.

On 2015-11-14 by Terry

Have 40g galvanised tank on farm, house water can't keep up with demand. Loses water when trying to fill a water through, have to prime pump in basement next to tank, sometimes it;s full of air sometimes its full of water.

Things we did in 2013 when we moved back to farm (after water was off since 2007): de-kinked water line in well, replaced part of pipe that had a small leak and replaced clogged up footvalve, re-pressurized the galv tank. decent water supply going now. I will need to turn water on to the barn for the winter... I can't keep losing my prime.

1) will replacing water tank with a "blue" one help?

2) If so what size? (the stores want to sell me a very small tank (but they are just thinking modest house supply)

3) should we go for & bladder or diaphragm?

4) keep galv. tank & do what to improve perf?

will also be replacing the T bar and all the fittings (regardless if keep galv tank or replace it).

Appreciate any input/advice.

I have 3 horses & a few goats (4x), a few rabbits (under 10) & chickens (under 10) in the barn, my father used to water a herd of dairy cows (twice a day)

On 2015-10-27 by clint

looking for a old fashioned pressure tank?

On 2015-09-08 by (mod) - one toilet flush: 11 pump on-off cycles = short-cycling

Before returning the equipment to Menards' (are you in Duluth?) take a look at the installation instructions for the water tank; confirm that the the air precharge is indeed 2 psi below the pump cut-in pressure setting;

IF the tank is waterlogged then perhaps the bladder has burst and indeed it'd be appropriate to switch it. Otherwise the problem is elsewhere.

Search InspectApedia for WATER PUMP SHORT CYCLING or find that link at the end of this page to read the diagnostic details.

On 2015-09-08 by sheila

i bought all new, the bladder tank to all the fittings, never really looked to see it was working correctly. Bought a little over a month ago. we was in the process of moving and remodeling, so i was just excited to have running water..

The old one kicked on every time u turned water on and with it being old i could hear it upstairs everytime i turned water on, so i replaced everything in basement, the tank and all the fittings.

Now its really quiet so i cant hear it, but i watched the switch today. My husband flushed the toilet and the switch kicked from 40 to 60 psi 11 times!

No other water running...did a load of laundry last night front load washer, and everytime water went to washer the switch was going 40-60psi all the time please help...

where do i start, im ready to return all to menards and get new again, its a 30 gallon presssurized tank, it has 38lbs of pressure in it, tank seems to have something in it, it dont seem to heavy though. Hard to really tell, i can rock it back and forth..

Question: Do you need to shut off all faucets when putting air into the water pressure tank?

After draining the system and turning off the well pump, when you re-inflate the water tank to pressure, do you shut off all the faucets again to recharge the tank? Or should the water tank hold air pressure even with the faucets open? - Takafoomi

Thank you Dan for the quick response. I do have a blue pressure tank with a bladder. Upon draining the system, there was not enough air pressure to register on the tire gauge. My Square D, a 30/50, seems to be cycling a fair amount more than it should be as of late.

I suspect that the bladder isn't holding a charge of air very well based on what I've read. I just want to see if I can get it to hold some air to be certain before I explore replacing the tank.. which is about 10 yrs old.

Reply: Don't fix an internal-bladder water tank just by draining it. You might need to shut off water into the home when adding air to a water tank.

With an internal bladder tank typically the starting pressure with no water in the tank is 2 psi below the pump pressure control switch cut-in pressure.

If the bladder is leaking you'll need to replace it or the entire tank/bladder assembly.

A ruptured bladder tank can behave oddly, including refusing to let water in or out of the tank depending on how the tank bladder collapses. And the pressure tank will begin to act like a bladderless-unit - consuming air over time even if a proper air charge is put into the tank.

Draining tanks or adding air to water tanks with internal bladder

If your water pressure tank uses an internal bladder you would not be fixing a waterlogged tank by draining it - so the discussion below only pertains to a bladderless water tank. Water tanks that use an internal bladder are discussed

at WATER TANK BLADDERS & CAPTIVE AIR.

Draining tanks or adding air to water tanks that do not use an internal bladder

If you are using the complete tank drain down so that the tank is fully empty, then you won't be pumping ANY air into the water tank; rather, starting with a tank fully empty of water and at local normal air pressure will be enough.

Details of that procedure are

at WATER TANK AIR ADD BY DRAINING.

If you are adding air to a water tank by pumping air into the system, details of that process are

at WATER TANK AIR ADD AT AIR VALVE.

In that case, if the air valve is mounted right on the water tank you don't need to close off water lines into the building, because air will be going right into the tank.

If the air inlet valve is mounted on building piping such as at the tank tee at the bottom of the bladderless water tank, it will usually but not always work to just pump air in at that point - much of the air will flow into the water tank. But in this case it's best to turn off the main water valve where the line exits the pressure tank and would otherwise send water into the residence. Then place the air charge into the tank.

For bladderless water tanks, don't worry if during the air pumping process some air enters the water piping in the direction of the well. That air will be pushed up into the water tank the next time the well pump cycles on. In fact that's just how snifter valves

(discussed at AIR VOLUME CONTROLS, WATER TANK) work.

Question: Why is the pressure in our water tank increasing and why won't the pressure switch kick on at low pressure?

The air pressure in the pressure tank goes from 28 psi to 40 psi in just a couple of days and as a result the switch wont kick on at low pressure . any ideas on why it would take on pressure - Anon.

Reply: Check for air leaking into the system, keeping the water tank pressure abnormally high

First make sure that the pressure you are reading is air pressure, not simply system pressure. Inside a water pressure tank, both air and water in the system will (nearly) always be at the same pressure.

If your water tank is one that does not use an internal bladder and if your well pump system is picking up air (for example from a leak in the well piping or a low-flow well) then the system could be sending a water-air mix at pump output pressure into the water pressure tank where air, naturally remaining above the water in the tank, is accumulating.

If your water tank is an internal-bladder type that was installed to replace a bladderless water tank 

AND if your well pump is a submersible unit (located inside the well) it is possible that air is entering the water tank bladder (where it does not belong) because the water tank installer failed to remove the snifter valve and in-well air drain valve/air inlet valve that were previously used to maintain the air charge in the bladderless water tank.

Details about snifter valves are

at AIR VOLUME CONTROLS, WATER TANK.

Or it's something else we haven't thought of. Let us know what you find, it will help other readers.

Question: Filling a swimming pool from the well resulted in low then lost water pressure - what might be wrong?

yes, awesome site with tons of info. my issue, 2 days ago i helped my blind neighbor fill his approximately 5,000 gallon pool... the next day he had low water pressure. then the following day just dribbles. according to him,

2 months ago with another issue with a burst pipe, he had somehow, bleed the air from his tank. today i will be checking that pressure. it sounds like he may have burst the bladder or burned the submersible pump.

any other tips or possibilities you can recommend? tyvm JOHN - bullweenkle

PS:

Little update... this morning we drained the tank. then checked psi, it is at 15 psi. tried to put in the 3 more lbs.. didn't take any, it seamed. did about 20 pumps from a bicycle pump.. no difference in pressure.

also after turning power back on, only heard a little hum. no water coming in. my worst thought, pump went bad?

Reply: problems that can occur when filling a swimming pool from a private well and pump system

Bullweenkle

Often when we fill a pool from a private well that process puts a lot of stress on the equipment and on the well itself. It's possible that the overtaxed well ran out of water; usually when that happens the well can recover in 24 hours, though there could be an exception, especially if it's a very deep well with a large static head and a very low original flow rate.

In a bladderless water tank air gets absorbed into the water over time - running water continuously for a short time ought not to deplete the air;

If as you suggest, this is a water tank with a bladder, then indeed a burst bladder would keep water from entering the system.

But I end with the same worry as you - that the well pump has been damaged by running for such a continuous period.

In sum, after a day of recovery time for the well there ought to be water in the well itself. Even with a burst bladder or saturated water pressure tank (no air charge), if the pump turned on and was running, you'd see some water pressure and flow in the home So either there is no power going to the pump (bad pump switch, bad pump relay, disconnected wiring, power off) or the pump is not pumping.

Check that hum you report. If the pump is in the well (a submersible), you wouldn't hear any pump noise when the pump is running. If the pump is above ground, then if it's humming and not pumping, that's pretty clear that the motor is not starting or the pump is jammed or an impeller is damaged.

If you confirm that there is power to the pump and my above summary is correct, it's time to pull the pump out of the well for an inspection and test.

Follow-Up from bullweenkle:

man your good... there was no hum.... the pump was replaced yesterday at a cost of 1200$. it was put in 1961. was old anyway. BTW, 1st changed out the pressure switch. old also. ty John

Question: Sporadic water pressure, fast, then slow, pump cuts on and off every few seconds

I have a Well-X=Trol pressure tank. I have water in house, but it is sporadic, running fast, then slow, & pump cuts on & off every few seconds. There is water coming from the air valve when you push that. So I assume it is water-logged.

Can I cut the power off, drain the tank, & turn it back on, let it fill, & it will add the air by itself? Please guide me so I can get this fixed. thanks - Gena Sager

Reply: the most common cause of well pump cutting on and off rapidly is lost air charge in the water pressure tank.

Gena, typically if you see water pressure varying significantly it's "fast" when the pump is on and "slow" when the pump is off and you're running off of the pressure tank delivery.

Water out of the air valve suggests the tank is water logged, as you guessed too. Yes you can turn off power, drain the tank entirely, let it just fill with air by gravity, then close it up and turn the pump back on. (Watch out for losing pump prime). Details on how to do this are

at WATER TANK AIR ADD BY DRAINING

A clogged water filter can also cause the pump to cycle on and off rapidly.

...

Continue reading at WATER TANK AIR, HOW TO ADD or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• WATER TANK AIR, HOW TO ADD
• AIR DISCHARGE at FAUCETS, FIXTURES
• SNIFTER & DRAIN BACK VALVES
• WATER TANK AIR VOLUME CONTROLS
• WATER TANK AIR ADD AT AIR VALVE
• WATER TANK AIR ADD at VALVE FAQs
• WATER TANK AIR ADD BY DRAINING
• WATER TANK AIR HOW MUCH TO ADD
• WATER TANK AIR CHARGE QUANTITY FAQs
• WATER TANK AIR HOW OFTEN TO ADD
• WATER TANK AIR INLET VALVE

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WATER TANK AIR, HOW TO ADD FAQs-2 at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER SUPPLY, PUMPS TANKS WELLS

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