Water Pressure Tank Air Charge FAQs

Is the Air Pre-charge Pressure in the Water Tank Correct?

How do I Know if there's enough air in the pressure tank?

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 2018-07-09 by Heather

Reply by (mod)

If the pump turns ON when the pressure in your system falls to the pump CUT-IN pressure and turns OFF when the pressure reaches the CUT-OUT pressure set at the pressure control switch

AND if the pump is not short cycling - turning on and off every few seconds, then the air charge is probably fine.

The actual length of time that the pump stays on depends on

How much water is being run how fast: if you open enough faucets and run enough water then the pump may run continuously.

When you turn water OFF the pump might take a few seconds or even run for nearly a minute to bring the pressure tank back up to the CUT-OUT or CUT-OFF pressure.

Where do I start to fix a pump short cycling problem?

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 every time 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.

I did a load of laundry last night front load washer, and every time water went to washer the switch was going 40-60psi all the time please help.

Where do i start, mm ready to return all to Menards and get new again, its a 30 gallon pressurized tank, it has 38lbs of pressure in it, tank seems to have something in it, it don't seem to heavy though. Hard to really tell, i can rock it back and forth. On 2015-09-08 by sheila

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 pre-charge 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.

 

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.

Signs of Air Leaks Out of the Pressure Tank

Water Tank Won't Hold Pressure After I moved It

@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 gauge 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 2017-05-08 by Nancy

Answer by (mod) -

Nancy

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).

Pump Runs for No Reason: Air Charge?

Our pump runs when we're not using any water - is this an air charge problem?

I have a cistern with a Slimline pump new pressure tank my pump runs and off but we have no water running in the house. Is it because the air charge is wrong? On 2016-02-09 by David

Answer by (mod) -

David I'm not sure I understand the problem nor the question.

First be sure that there really is no water running - such as a pipe leak or a running toilet that you hadn't noticed.

Then see the diagnostics at WATER PUMP INTERMITTENT CYCLING 

How do I Add Air to a Buried Water Tank?

Illustration above of two options for burying a water pressure tank below the frost line is adapted from Pentair's Wellmate underground tank installation instructions that we cite and link-to just below. Clicking the image links to Pentair's Wellmate underground tank installation instructions.

My underground water tank is saturated and there's no Schrader valve to add air

There is nothing about adding air to an underground tank that is saturated.

I can't put pressure into the buried water tank from a Schrader valve. And we have constant water pump short cycling.

I can't vacuum water out of tank with a shop vac. Why is there hardly any information on underground water tanks? On 2016-02-07 by Larry L

Solutions suggested by (mod) - how to restore air charge in a buried water pressure tank

Larry

Because buried water tanks with no physical access are less common unusual you may have trouble finding specifications, photos, history, procedures.

I think that's why you haven't found much information, but here at InspectApedia we do have some advice for buried water tank owners.

See this

• Pentair, PENTAIR WELLMATE RESIDENTIAL & LOW PROFILE TANKS UNDERGROUND INSTALLATION INSTRUCTIONS [PDF] (at aquascience.net) Filtration & Process 5730 North Glen Park Road, Milwaukee, WI 53209 P: 262.238.4400 | F: 262.238.4404 | www.pentairaqua.com | Customer Care: 800.279.9404 - local backup copy saved as Underground-Water-Pressure-Tanks-Pentair.pdf

To add air into the buried water pressure tank:

If your tank was properly installed it should have an accessible air valve.

If not then you will need to find a way to allow air to enter the tank while you use a pony pump to draw water out of the tank. In the illustration above Pentair shows a "surface air check" tube that should allow for checking and adding air to the buried water tank.

For other buried water tank installations adding air might be possible by working with pipes in the building - for example by opening the pipe that sends water into the tank from your water pump - to allow air in, or by excavating the top of the tank to see if there's a tapping into which you can add a Schrader valve.

With the water line into the water tank opened - say in your building or in an outdoor pump house (or at the tank if you excavate it), then you can attach a pony pump to the water tank outlet line at a convenient location and then pump water out.

That will draw air through the buried water tank's inlet into the tank.

Less likely: you may be able to force air into the tank by back pumping air through the water supply line exiting the tank, after installing a suitable fitting, valve, and Schrader valve.

Watch out: if the internal bladder of your water tank has perforated or burst then you'll need to replace the entire tank assembly unless the tank is a model that permits bladder replacement.

In our article on water tank bladder repair procedures we include this

WATER TANK BLADDER TEST PROCEDURE that may help you determine if your tank simply needs air or if it needs replacement.

Water Comes out of the Air Valve on the Water Tank

If water came out of air valve is the water tank bladder shot?

(Jan 27, 2016) usnabink2000@gmail.com said:
I have a bladder air water tank when I checked the air pressure, I had a little bit of air then water. Is my bladder part busted and do i need a new tank?

Reply by (mod):

Chances are the tank bladder has burst. On some tanks the bladder can be replaced, otherwise it's time for a new water pressure tank.

See WATER TANK BLADDER DIAGNOSE, REPAIR or REPLACE

My well pump short cycles and when I check the air charge valve water spurts out

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 attach the pressure gauge On 2016-02-07 by Patrick k

Reply by (mod)

When water squirts out of your bladder type water pressure tank that's telling me that the internal bladder that normally keeps the water and air in separate chambers is burst or leaking. If your tank has a replaceable bladder that's what's needed.

Else you'll need to replace the whole water tank assembly.

I checked my bladder tank: water comes out of the air hole

2 yrs ago I had the pressure switch on my bladder tank replaces by a friend, can't remember the reason he took off the pressure switch gage but he did and now it doesn't have a gage on it. Last week the switch is banging every time water is used. I know I need to replace tank.

I checked the air pressure, there is none. Water comes out the air hole. Tank is full of water.

I assume bladder broke.

I have another tank to replace it. (Used) husband died 3 yrs ago or he would already have this fixed.

Anyway, so I turn off breaker to pump, turn off valves in and out, have the hose already attached to drain tank.

Suppose it actually goes smoothly and I attach the other tank properly.

How do I tell without a gage how much air to put in and do I add air before I turn pump back on? I have a tire gage but will that work instead of an actual gage? On 2015-11-03 by hodaka

Explanation by (mod) - burst bladder can trap water in the water tank

You may have trouble getting the water out of a tank with a burst bladder as the bladder may collapse and cover the tank outlet; if so just get help to take the water-heavy tank outside;

The air pre-charge in an internal bladder tank needs to be 2 psi below the pressure switch cut-in pressure.

Bladder Type Water Tank Shows NO Air Pressure

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.

Air Pressure in the Water Tank Creeps Up on its Own - Pump won't Turn ON

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.

Water pressure tank pressure is slowly increasing

My pump/tank runs at 30-50PSI, and had slowly crept to running at 38-58PSI.

I adjusted the pressure switch back down to 30-50. Doing this, I noticed on water demand (washer, toilet, faucet, etc) the pressure drops about 5PSI during the demand.

If my tank is at 35PSI and a demand is made, pressure immediately drops by 5PSI to 30, and turns on the pump.

Is this normal? If not, what is the problem (dirty water filter, bladder low pressure or air leak, etc)?

The problem is not caused by the pressure gauge, which is fully functional. It is water demand that causes the gauge to drop 5psi. When the gauge is on ANY pressure, it drops 5psi upon demand, and springs back up when demand is removed. (Apr 3, 2015) Bob Chervenock

Reply: excess air is being accumulated in your water pressure tank

Bob

That sounds as if there is an air volume control or snifter valve on your pump and well system that is not working properly: additional air is being added to the system and not being automatically purged.

Take a look at these two topics. If any of the controls we describe there is not working properly that can cause air to accumulate in the pressure tank and pressure to creep up just as you describe.

• WATER TANK AIR VOLUME CONTROLS
• SNIFTER & DRAIN BACK VALVES

Other possibilities are listed In the ARTICLE INDEX found among the Continue Reading links at the end of this article in several diagnostic articles such as

• WELL WATER PRESSURE DIAGNOSIS

A small leak in a tank bladder can cause a creep-up of tank pressures but if that were happening at your system you'd see that the pressure did not keep falling down to the same low point.

Can air accumulate in the water pressure tank?

In the past month, we have had air in our water lines whenever the sprinkler system is running and we are running water in the house (shower, sink, etc).

I think we have a bladder style tank because of the Schrader valve near the top. I checked the pressure tank (the last time this happened and the gauge was down to 30psi (I have never see it this low) and the compressor was not cycling. Also, there was almost no water in the tank (80 gallon and I could move it easily).

I had a plumber come out to check the system and he made a few adjustments, but said everything looked fine. Also, the tank is filling to just under half. In the past it usually held to around 3/4 full. We are still having this problem, even after the plumber checked the system. On 2017-06-11 by Drew

Answer by (mod) - yes with some automatic air controls that malfunction

Drew:

While a pressure tank might accumulate an air charge if there is air in the water supply system the tank itself would not be likely to be responsible for its source.

More likely there's either a malfunctioning air volume control device or well snifter valve that's injecting too much air or there is a leak in the well piping or low water in the well.

Please see

• AIR DISCHARGE at FAUCETS, FIXTURES
• SNIFTER & DRAIN BACK VALVES
• WATER TANK AIR VOLUME CONTROLS

to read the more-likely causes of the problem you describe. Take a look at that article and then ask more questions as needed.