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How to Diagnose & Repair Air Discharge from Water Supply Piping or Plumbing Fixtures       How to diagnose & fix sputtering air coming out of faucets Causes of air blasts or bubbles in water supply piping & causes of excess air in water pressure tanks Significance of large bursts of air at faucets & Significance of fine white bubbles in water taken from a faucet Signs of loss of well water & Signs of well piping leaks Signs of water pump failure Water pressure tank air volume control problems How to restore lost air in a building water pressure tank Excess air in the water pressure tank or well piping system: causes and cures AIR VOLUME CONTROLS, WATER TANK - separate article AIR INLET VALVES - separate article SNIFTER VALVES - what is a snifter valve used on a well water system and how do they work? Hidden and antique air volume control valves and features can explain well pump rapid cycling problems & air discharge troubles at faucets & fixtures Questions & Answers about air discharge at plumbing fixtures and/or excess air in water pressure tanks or in well water systems References

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How to diagnose & fix air coming out of faucets: this article describes the causes of air discharging from building water supply piping or plumbing fixtures or the sources of excess air in water pressure tanks, water supply piping, or other plumbing fixtures. If air blasts out of your faucets or fixtures we explain what's going on, why it's a problem, and how to diagnose and fix the trouble. Some air discharge or bubbling issues in building piping are not serious, while others could spell expensive trouble. We list the various causes of air discharge at faucets or shower heads and how to correct each one.

Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.

Causes of Air Discharge from Building Plumbing Fixtures

Readers of this document should also see Water pump and pressure tank repair diagnosis & cost an specific case which offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost. The illustration at page top is courtesy of Carson Dunlop, Inc. in Toronto. The round air volume control photographs shown here and just below are courtesy of Ben Langston.

WATER PUMP CONTROLS & SWITCHES contains advice on how to adjust water pressure and water pump cut-in and cut-out pressures.

Air blasts or air bubbles coming from plumbing fixtures such as faucets, showers, or toilets may be a temporary problem that cures itself or it may be a sign of a deteriorating water well. Here we list various causes of air in building water supply piping and fixtures to help in diagnosing and repairing this problem.

If your well tank is a "captive air" or bladder type pressure tank such as the Well-X-Trol™ series see WATER TANK BLADDER PRESSURE ADJUSTMENT. Bladder type or captive-air water pressure tanks and their repairs are described at WATER TANK TYPES and at WATER TANKS HOW THEY WORK.

Question: Why is air coming out of my faucets, what does it mean, and what can I do to diagnose and fix the problem?

For a couple months now we've had excessive air in our water lines, similar to after there has been a power outage and the water spurts out of the faucets. I'm trying to figure out a solution to our water issues. We continuously have air in our water supply at all faucets, toilets, and showers; the air is intermittent, and spurts out while water is running, anywhere from immediately after faucet is turned on to a couple minutes later (in shower, for instance). Flushing the toilet results in the pipes or toilet valve banging. we have a well that's 204' deep, and the submersible pump was replaced in July 2005 (five years ago).

Our water pressure tank is working fine, turning on/shutting off at 30/60. After shutting off, with no water running, the pressure holds steady at 60. When the pressure tank is drawing water from the well, you can hear and feel the pipe from the well drawing in a lot of air from the well the cold water has the air problem much more than the hot water for whatever reason (please advise!), on two of our faucets with separate hot/cold handles, the cold water won't come out anymore.

Did the spurting of the air/water lodge mineral deposits in the valve or something to prevent cold water from coming out, but allowing hot water to flow? the flow rate out of our faucets varies from normal at times to very low pressure we don't have a water treatment system we don't have a venturi valve that I know of (we bought the house 5 years ago) or that I can find

I don't know the static level or the recovery rate of the well, and with our air/water problem, I'm not confident that I'd get a good reading.

A licensed plumber came out yesterday (very kind, offered a free estimate) and looked at the pressure gauge on the pressure switch (between the incoming supply line from the well and the pressure tank) and concluded that it's something to do w our well or well pump. He suggested that either the well may be running dry or that the screen may be clogged up. He suggested I get some friends and pull up the well pump and examine it. - T. C., Purcellville, VA

Answer:

From your description it sounds as if your well water level is dropping and the pump is sending a mix of water and air into the building piping. If that turns out to be the case, it might be possible to increase the well yield - a step less costly than drilling a deeper or new well. But first take a look through the causes of air in building water piping that we describe just below. If the problem were simply a leak in the water piping between well and house, for example, that would be less costly to repair.

List of common causes of air in water, or air coming out of plumbing faucets and fixtures:

Consider that because under normal conditions building water supply piping and fixtures are pressurized with water, a leak or opening in a pipe or fixture would be expected to leak water out, not air in to the plumbing system. But there are some exceptions that we describe below. Air blasts, or air sputtering out of plumbing faucets means there is air in the water supply system. Below we diagnose the most likely causes and thus the cures for this problem.

  AIR DISCHARGE at FAUCETS, FIXTURES
    Air Overcharge in Pressure Tank
    Burst Water Pressure Tank Bladder
    Bad Check Valve
    Leaks in the Well Piping
    Loss of Water in the Well
    Damaged Well Pump
    Defective Air Volume Control
    Gases in the Well and Water Supply
    Air Discharge from Hot Water
    Water Treatment Equipment
    Other Sources of Air in Piping

Watch out: a hole or leak in a well pipe or a defective or improperly installed check valves on a private pump and well system can also cause air discharge from the building's faucets. A faulty check valve that allows water to drain back into the well causes negative pressure or "suction" that can draw air and contaminants into the well piping or into the well itself. See details at CHECK VALVES, WATER SUPPLY.

Experts note that when the pump shuts off, if there is a hole or leak in the well piping, the hole allows air into the well line; when the pump is running, water sprays out of the same hole, possibly adding to rust and debris in the well and the pumping of silty or dirty water into the building.

Why Air Overcharge in the Water Pressure Tank Can Cause Air Discharge at Plumbing Fixtures

If in placing an air charge into a bladderless steel or fiberglass water pressure tank the tank is overcharged air may flow out of the tank, through piping and out of plumbing fixtures when water is turned on. This condition only occurs if the tank is one that does not separate water from air using an in-tank bladder. In this case the problem is self-correcting, typically in just a few minutes of running water at each fixture, as excess air flows out of the tank, through piping, and out at fixtures. As the water pump cycles back on and water is pushed back into the water tank, operations will resume normally. For details see WATER TANK AIR, HOW TO ADD and WATER TANK AIR HOW MUCH TO ADD.

How a Burst Water Pressure Tank Bladder Can Cause Air Discharge at Plumbing Fixtures

If a "captive air" bladder-type water pressure tank has a ruptured bladder, depending on the total air charge or pressure, air may be forced out of the pressure tank and through piping and fixtures as above. As with our first example, the air flow will be temporary. But in this case the water pressure tank will become waterlogged and the water pump is likely to be short-cycling before long (see WATER PUMP SHORT CYCLING). A new water pressure tank or a bladder replacement will be needed. We discuss captive-air water tank bladders, their maintenance, bursting, and repair, at WATER TANK BLADDERS & CAPTIVE AIR.

How a Bad Check Valve can Cause Air Discharge at Plumbing Fixtures

A defective or improperly installed check valve on a private pump and well system can also cause air discharge from the building's faucets. A faulty check valve that allows water to drain back into the well causes negative pressure or "suction" that can draw air and contaminants into the well piping or into the well itself.

See details at CHECK VALVES, WATER SUPPLY.

Watch out: when diagnosing the cause of air discharge from building faucets, it's easy to misdiagnose the cause: from inside the building the symptoms of a bad check valve (loss of prime, possibly air discharge at plumbing fixtures) can look a lot like a hole in the well piping, especially if the hole is in the pipe rising inside the well itself (also causing loss of prime, air at faucets) - as we discuss further just below.

How Leaks in the Well Piping Can Cause Air Discharge at Plumbing Fixtures

Experts note that when the pump shuts off, if there is a hole or leak in the well piping, the hole allows air into the well line; when the pump is running, water sprays out of the same hole, possibly adding to rust and debris in the well and the pumping of silty or dirty water into the building.

While water piping is under pressure and water leaks out rather than air leaking in, if we have the combination of lost water pressure (for example during an electrical power loss or a well system being shut down), and leaks in the well piping, as water drains backwards into the well air may be drawn into the water piping through piping leaks.

If the piping leak is inside the well casing where plenty of air is available, and if the well piping includes a defective (leaky) foot valve or check valve in the well, this cycle could repeat and building occupants may see recurrent air discharge from plumbing fixtures. See WELL PIPING FOOT VALVES.

You may be able to diagnose this problem by turning off all water supply in the building and watching what happens to the water pressure gauge at the pressure tank.

If the water pressure falls slowly even when you are sure no water is running in the building, there is probably either a bad foot valve or check valve in the well, or a leak in the water piping between the well and the building. But watch out - water pressure gauges can be inaccurate or slow to respond to changes in water pressure - see WATER PRESSURE GAUGE ACCURACY.

If there is a severe well piping leak or a water piping leak or running plumbing fixture in a building the well pump may begin to run continuously - see WATER PUMP WONT STOP RUNNING.

See Water Supply/Drain Pipe Leak Types for details on diagnosing types of water piping leaks. Also see Repeated Loss of Pump Prime for additional diagnostic help with well piping and foot valve leaks.

How Loss of Water in the Well Can Cause Air Discharge at Plumbing Fixtures

A falling water table or decline in well recovery rate may cause the well pump to send a mixture of water and air into the well piping and building. If this condition is occurring you might notice that the air discharge at plumbing fixtures is intermittent: when no water has been run overnight and the well has recovered, once existing in-piping air has blown out, the water flow may appear normal, without air discharge.

But as well water level drops and the well is slow in recovering, the air discharge problem will return. In sum, these well or well and pump conditions can cause air to be delivered by the well pump into the building's water supply piping:

If your Well Yield is inadequate (inadequate WELL FLOW RATE) water level in the well may drop low enough for air to enter a submersible (in well) pump or into the foot valve. The combination of a too-small Static Head (water reserve) in the well and a poor flow rate make this problem more likely. A well that has performed adequately in the past may no longer have an adequate yield for a variety of reasons: drought, a drop in the water table, drilling of new wells nearby, or yield loss due to mineral clogging of rock fissures that feed water to the well.

If the well pump is too large incapacity (pumping rate) for the well's safe yield then air may be drawn into the well pump and water piping when the pump drops water level in the well too low.

The safe yield for a well may change if the water table drops. Then, if the well pump output rate exceeds the safe yield for the well, air may be injected into the building water piping and the well pump may be damaged. See Well Yield: Well Flow Rate where we define safe well yield.

See Water pressure Later Returns "on its own" - for symptoms of loss of water in the well and slow well recovery rates. See WATER PRESSURE LOSS DIAGNOSIS & REPAIR for our complete article series on diagnosing loss of water or water pressure at a building.

Defective or Damaged Well Pump Can Cause Air Discharge at Plumbing Fixtures

It is possible that a failing well pump may introduce air into the water supply piping system due to cavitation (a vacuum forming inside the well pump mechanism), causing dissolved gases to come out of solution. Cavitation and air leaks into a water pump may be more likely with an above-ground jet pump and less likely with a submersible in-well pump that would be expected to be always submerged in water. See WATER PUMP TYPES & LIFE EXPECTANCY.

If a new well pump has been installed and is over-sized, the level of water in the well may be drawn down too rapidly when the pump is running, resulting in air entering the pump and being delivered to the building. This condition can also occur in times of drought or if your well is running dry.

Defective Air Volume Control Can Cause Air Discharge at Plumbing Fixtures

An air volume control device may be installed on some bladderless water tanks to attempt to keep the proper air charge in the water tank. If the air volume control is leaky or not working properly it may be overcharging the water tank with air. If this is the case the air discharge from plumbing fixtures will be chronic. See WATER TANK AIR VOLUME CONTROLS.

Gases in the Well and Water Supply Can Cause Air Discharge at Plumbing Fixtures

In some areas gases, including potentially dangerous explosive methane gas, may leak into the water supply and may be delivered into the building water piping from a well.

Watch out: methane gas in well water is a pollutant and may be explosive. According to experts such as the New Hampshire Department of Environmental Services,

Methane at high concentration is explosive and thus there is a fire hazard if large amount of water with methane are used near an open flame in a closed space. The presence of methane gas in water can be simplistically detected by agitating a small volume of water in a plastic container in an outdoor location and attempting to ignite the gas released. Have a neighbor present when you try this testing. If you have such a well you should contact your local department of environmental services and your building department.
Lowering the settings of the pump’s start/stop switch and/or providing an air release vent on the water storage tank at the high point of the stored water might allow this “off gassing” to occur at a point other than your faucet. Since this is a natural condition, and no damage is caused, there is no need to take any particular action.

Dissolved gases may also be present in water but would not normally appear as bubbles or air blasts at a faucet. These include radon, carbon dioxide, hydrogen sulfide (rotten egg smell), or other gases from dissolved organic matter or chemicals. But in some deep wells water at the well bottom, at higher pressure, may hold dissolved gases that convert to bubble form when water pressure is reduced to ambient air pressure at building faucets. Changes in water temperature also affect the amount of gases that remain dissolved in water - warming water drives gases out of solution.

See WATER POLLUTANT SOURCES

Air Discharge from Hot Water Faucets

Watch out: if you find air discharging only from your hot water faucets a dangerous condition may be present: the hot water heating system may be too hot, risking scalding or even water heater explosion. Turn off power or fuel to the water heater itself and call a licensed plumber immediately.

Problems with Water Treatment Equipment Can Cause Air Discharge at Plumbing Fixtures

Water treatment equipment can also inject air into a building water supply. Water treatment to remove odors or gases from the water supply may use venturi air injectors intended to remove iron, manganese, or odors. Properly installed these devices should not send air out of faucets. But the following conditions can cause air injector treatments to place excess air in the building water supply piping:

• A change in the water pump output rate may cause a mis-match between the air injection rate at the injection nozzle or venturi and the total water quantity being delivered to the building
• A change in water piping that fails to properly pitch water supply piping to an excess air relief valve
• A failure of the excess air relief valve to continue to release air - the valve may need cleaning or replacement
• An improper adjustment of the air-to-water ratio at the air injection nozzle or venturi. Your water treatment company technician can reduce the level of air injection to the minimum needed to remove the objectionable odor, iron, or manganese.

Other Sources of Air in Water Piping - Work on Municipal Water Mains or Private Well Piping

There may be other causes of air discharge from building water supply piping, including the ones we list below. Leaks in well piping anywhere between the well and the building can introduce air into the well piping and water supply system. Temporary air introduction into municipal water supply piping when work is being performed on the water system. Usually such conditions are temporary. Faucet aerators: Fine white bubbles in the water coming from a faucet may simply be due to the faucet aerator designed to prevent splashing. SNIFTER VALVES on submersible pump and well systems that use a bladderless water pressure tank (or whose bladderless water tank was replaced with an internal bladder water pressure tank) can push excess air into the water pressure tank. If a bladderless water tank that used a snifter valve system is replaced with a new internal-bladder tank you may need to have a plumber pull the well piping to remove the (now no longer used) drain and vent found inside the well. Even if the bladderless water pressure tank was replaced with a new bladderless tank, if the snifter valve system was left in place but the excess air vent was not installed on the new tank (or is not working) you'll want to provide or repair these components. CONTACT us to suggest other causes of air in water supply systems.

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Frequently Asked Questions (FAQs) about air discharge from plumbing fixtures or excess air in water supply systems

Question: Air bursts coming out of plumbing, & my well pump won't shut off

I have a 3/4 Hp 120v single line shallow well pump for my house. The well head is located about 50ft from pump. I also have a well mate water pressure tank with good pressure in it. I have live in this house for 3 years and have had no problems with water supply or pressure to the house. I have check the pump pressures in the past being 30psi for pump to turn on and 53psi to turn off pump.

I can hear the pump run while taking a shower as its just on the other side of the wall. and normally the pump will run once and shut off while the shower is still running. It was normal up until 2 days ago.

Now my pump with come on and will not shut off while the shower is running. Also I am getting air busts out of every fixture. I have turned down the off pressure to the pump to 45psi and this seems to help sum. I can hear the pump cavitating and the cavitation and air busts seam to be worse the higher the pressure goes higher.

I have a check valve in the supply line to the pump about 10inchs from the pump. I have no drop in pressure after 4hrs of running no water. My question is where is the air coming from? Could my pump be going bad and cavitating that much air into my system? Or does there have to be an air hole in my pipe somewhere between my pump and foot valve? or could my well low on water? How do I diagnose this problem? - Thanks Derek

Reply: deteriorated well flow rate, well piping leak, or other?

Derek, regarding your question about well pump not shutting off:

The air bursts coming out of your plumbing suggest that either the well flow rate has deteriorated (the pump is getting ahead of the rate at which water flows into the well) or there is a leak in the well piping (air leaks into the piping when the pump is not running).

If it were a pipe leak and given you've got a one-line jet pump, you might eventually find the pump loses prime and you get no water at all (don't let the pump keep running dry or it may be damaged).

But unfortunately I suspect that the well flow rate has deteriorated.

Check to see if the water pressure continues to drop after the pump has turned itself off and when you are NOT running more water in the house. If so there's a leak in the piping or a bad check valve or foot valve.

Take a look at our diagnostic suggestions at WATER PUMP WONT STOP RUNNING

If not, bad news, lost well water.

Question: air discharge in plumbing traced to well piping leaks

I got same problem last time it turned out to be leak in the threads on the pipe between he well and intake side of my pump having problems again about a month still cant figure it out might have to call a well pro. - Shu

Reply:

Thanks Shu. Indeed leaks in well piping between the well and the building can introduce air into the piping. We've added this tip to our sources of air discharge at fixtures.

Question: air out of fixtures - artesian well feeds holding tank pumped then into building

I have been getting air out of my fixtures for the last month. My system is "unique" I have a artesian well that constantly drips water at a low volume/pressure into a underground holding tank then a shallow well jet pump sucks that out of the tank and fills an old bladder-less tank. Normally when my underground tank is full my runoff line drips out the excessive water, but lately my jet pump has not been cycling on and off it seems like it is just pumping water somewhere and running my underground tank empty, if I unplug my pump the tank will fill and runoff after 2 hours or so.

I have replaced my pump and my air volume control with very little or on change. When I unplug my pump and turn it back on after 2 hours it runs fine and with good pressure for a few hours and reverts back to staying on and sucking my underground tank dry. Got any Ideas? - Devin Snyder

Reply:

Devin I'd check for a leak on the water supply system piping. Start looking carefully at the piping between the water storage tank and the building. I'm guessing that your shallow well jet pump is located in the building where it pressurizes a bladderless water pressure tank.

A leak in water piping on the inlet side of the jet pump can suck air into the water lines when the pump is drawing water from the storage tank.

Or of course there may be some other snafu we haven't thought of. Keep us posted - what you find will help other readers.

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Questions & answers or comments about air discharge at plumbing fixtures and/or excess air in water pressure tanks or in well water systems.

Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

• Ben Langston, generously contributed the photographs of round disk-type air volume controls used at the top of this article.
• Alan Carson, Carson Dunlop, Associates, Toronto, has permitted our use of the well and water pump system used at the top of this and some other pages at our website.
• Thanks to - Tim Chambers, Purcellville, VA for discussing the causes and effects of air in a building's water supply piping - July 2010
• Air in Drinking Water, Environmental Fact Sheet, New Hampshire Department of Environmental Services, 29 Hazen Drive, Concord NH 03301 - web search 07/14/2010 original source: http://des.nh.gov/organization/commissioner/pip/factsheets
  /dwgb/documents/dwgb-3-18.pdf
  The purpose of this document is to identify possible explanations for fine white bubbles that are sometimes seen in drinking water immediately after the water is taken from a faucet. The condition is similar to effervescence. These bubbles disappear within approximately one minute after the water is drawn from the tap.
  DES does not believe that there is a health significance to these air bubbles, however, they may create a safety risk as explained below. They may also indicate improper physical conditions in pumps, pipes, or other water system equipment. There are numerous possible explanations for these bubbles.

Water Supply & Drain Piping, Wells, Pumps, Water Supply Equipment

• Access Water Energy, PO Box 2061, Moorabbin, VIC 3189, Australia, Tel: 1300 797 758, email: sales@accesswater.com.au Moorabbin Office: Kingston Trade Centre, 100 Cochranes Rd, Moorabbin, VIC 3189
  Australian supplier of: Greywater systems, Solar power to grid packages, Edwards solar systems, Vulcan compact solar systems, water & solar system pumps & controls, and a wide rage of above ground & under ground water storage tanks: concrete, steel, plastic, modular, and bladder storage tanks.
• Smart Tank, Installation Instructions, Flexcon Industries, 300 Pond St., Randolph MA 02368, www.flexconind.com, Tel: 800-527-0030 - web search 07/24/2010, original source: http://www.flexconind.com/pdf/st_install.pdf [Copy on file as /water/Smart_Tank_Flexcon.pdf ] -
• Typical Shallow Well One Line Jet Pump Installation, Grove Electric, G&G Electric & Plumbing, 1900 NE 78th St., Suite 101, Vancouver WA 98665 www.grovelectric.com - web search -7/15/2010 original source: http://www.groverelectric.com/howto/38_Typical%20Jet%20Pump%20Installation.pdf, [Copy on file as /water/Jet_Pump_Grove_Elect_Jet_Pumps_1.pdf ] -
• Typical Deep Well Two Line Jet Pump Installation, Grove Electric, G&G Electric & Plumbing, 1900 NE 78th St., Suite 101, Vancouver WA 98665 www.grovelectric.com - web search -7/15/2010 original source: http://www.groverelectric.com/howto/38_Typical%20Jet%20Pump%20Installation.pdf, [Copy on file as /water/Jet_Pump_Grove_Elect.pdf ] -
Cooperative Extension, School of Forest Resources, web search 07/24/2010, original source: http://pubs.cas.psu.edu/FreePubs/pdfs/XH0002.pdf

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.

The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author. Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.

• Crystal Clear Supply provides portable ceramic water filter purifiers and portable reverse osmosis water treatment equipment - see http://www.crystalclearsupply.com/category_s/7.htm
• ...