Q&A on How to Add Air to a Water Pressure Tank

Ways to Add Air to the Water Tank if There's No Air Valve (Schrader Valve)

My well pump is cycling on and off and water is not entering the holding tank. How do I pressurize it?

I need help. My well is cycling and the holding tank is not filling up with water.

How do I pressurize it? There is a pressure valve on the pump. But I cant seem to locate a valve stem anywhere. HELP~!! - Tammy

Reply:

Tammy, there are three approaches to re-charging the air in a water pressure tank - please read about them in the article above. If your tank doesn't have an air valve you can recharge it by draining.

1. Drain the water tank using a garden hose and allow air to enter the tank - details are

at WATER TANK AIR ADD BY DRAINING - this is perhaps the easiest and simplest method of getting air into a water tank BUT\

Watch out: if your water tank uses an internal bladder to keep water and air separate, and if the water tank bladder has burst and the tank is flooded OR if the water tank bladder has stuck to itself, simply trying to drain the tank won't work.

So you might want to read WATER TANK BLADDER STUCK to ITSELF first

2. Use or repair the water tank air volume control, if one is installed - details are

at WATER TANK AIR VOLUME CONTROLS

3. For deep well submersible pump systems there may be a snifter valve that will add air to the water tank.
   
   See that explanation at SNIFTER & DRAIN BACK VALVES
   
   
4. Look once more: If there is an air valve you can use the water tank air inlet valve or tire valve or "schrader valve"
   
   to pump air into the tank IF there is an air valve on the tank itself (and sometimes adding air at an air valve installed on the tank tee at the tank bottom can also work - details are

at WATER TANK AIR ADD AT AIR VALVE

I can't find where to add air to the water pressure tank

I recently had a water softener installed because my well water is very hard. The water softener installer asked what my water well pressure was set at on my well and tank - I told him 30 - 50 psi.

He stated the system pressure needs to increase to 40-60 or perhaps even 50-70 because the water softener may not work correctly with pressures below 40 psi.

Since I am a DIYer and an engineer, I figured, how hard can adjusting the pressure really be? I Googled it and all of the articles said that after adjusting the pressure switch, I need to set the water tank pressure about 2-4 psi below the cut-in pressure, i.e., if I raise it from 30-50 to 40-60, then the tank pressure would need to be set between 36 and 38.

Here is where the issue is - I could not find a Schrader valve on my tank to increase the tank pressure to 36-38.

I did some tank research on my tank and it appears to be a bladderless tank - specs as follows:

Manufacturer: AO Smith Water Systems Division
Description: Hydro-Pneumatic Pump Tank
Model #: PZ 120 3
Max Work Pressure (PSIG): 75
Manufacture year: 1994
Volume: 120 gallons
Height to top of dome: 64.5”
Height of cylinder not including dome top: 60”
Diameter: 24” Water outlet: 1.5” NPT at 3” from the bottom on one side
Water inlet: 1.5”NPT at 12” from the bottom on the opposite side from outlet
Air ejector port: 1.25” NPT at 33” from the bottom on the opposite side from outlet
Top port: 1” NPT Plug

Since it appears to be a bladderless Hydro-Pneumatic Pump Tank, I have the following questions:

• How do I adjust the tank pressure when there is no bladder - do I just adjust the pressure switch from 30-50 to 40-60 and that is all that is needed?

• How is the system water pressure maintained at all of my faucets and sinks when the tank does not have a bladder to keep the system pressurized?

• Does a bladderless tank decrease the life of the pump?

Thanks in advance for your help! On 2016-09-24 by TankHelp

Answer by (mod) - boost water pressure for water softener to work? Really? - Ways to add air to this pressure ank

Tank

Your water tank, the AO Smith PZ 120 is a galvanized water storage tank that may not be delivered with an air valve.

But there are several ways to add air to the system

1. by draining the tank (with pressure and pump off, or
2. by a snifter/drainback valve combination on the well piping, or
3. by adding a Schrader valve at a tank tapping.

A bladderless water tank does not reduce the life of a water pump per-se, but indeed IF the air volume control system used to keep a proper air charge in the pressure tank is itself not working, then the pump can end up shorty cycling and face a reduced life.

In those installations often I see an air valve on the tank tee at the tank bottom. By shutting off the water main between tank and house I can normally still use that valve to get air into the tank for pressure pre-charging, a procedure we use if simply fully draining the tank of all water, then turning the system back on doesn't work.

1. Your tank has several tappings including right on the tank top where there is a 1" NPT plug. That plug can be replaced with a 1" fitting that will step down to a 1/4" or 1/8" npt Schrader valve for adding an air charge if necessary.

2. The system pressure is produced by the water pump, not the pressure tank. The tank is simply giving you a bit of water draw-down time before the pump has to turn on; otherwise the pump would be short cycling and burn-up.

3. A bladderless tank does not decrease the life of a water pump per-se. However maintenance of the air volume in the any water tank is critical to avoid pump short cycling - an event that does reduce pump life. Maintaining the air charge in a bladderless tank can be a bit more difficult than in a tank with an internal bladder.

But I wouldn't rush to change the tank before knowing more about the water system and the well. E.g. your well flow rate may be so poor that a larger water tank was needed; and e.g. 2, if your system is old and uses a submersible well pump, changing to a bladder type tank could require also pulling the well piping to remove an old snifter valve system - increasing the changeover cost.

See the details at SNIFTER & DRAIN BACK VALVES

But I'm surprised at the pressure insisted-on by your installer. I would be sure to get my hands on the installation and operation manual for the water softener. There you will most likely see operating pressure specifications for the unit. If you don't, then I'd give the manufacturer's technical support a call.

See WATER PUMP SHORT CYCLING CAUSES

and

See WATER TANK LIFE EXPECTANCY

Water Pressure Surging versys Water Tank Air Charge

When water is turned on, after a couple of seconds, it begins to surge and pulses harder and softer after that.

Well pump pressure jumps to about 65 psi in about 5 seconds then the pump shuts off

I love this website and appreciate the good work you are doing.

I am trying to diagnose a problem with my well. I have looked through your site and I’m not sure I saw a problem quite like this one.

The symptom is when water is turned on, after a couple of seconds, it begins to surge and pulses harder and softer after that. I live in Sacramento, have an outdoor well and tank which is 220 gallons, galvanized steel, and I believe to be bladderless. I have the pressure switch set to 40 -60 psi.

When I watch the water pressure gauge, when the water is turned on, it goes down to 40 in about 7 seconds, the pump kicks in and it jumps up to about 65 psi in about 5 seconds and shuts off. It continues this cycle continuously while the faucet remains on.

After reading your website, I was hoping I had a waterlogged tank. I shut off the power, opened the hose bib.

The tank emptied pretty fast, but kept gurgling with little bits of water coming out every so often. I shut the bib off, restarted the pump and it did the same thing. It doesn’t seem to be filling the tank. Any ideas on how to proceed?

Thanks! - Max

Reply: Sounds like a waterlogged pressure tank.

Max,

Your description sounds like a water-logged pressure tank. Your observation that when you opened the hose bib "The tank emptied pretty fast, but kept gurgling with little bits of water coming out every so often." might mean that the tank was not really emptying at the hose bib. Rather the first water that came out was that which was under pressure.

After that, the full tank was dribbling water slowly out of the hose bib as intermittently a little bubble of air found its way back into the tank to thus allow a little more water to escape. That gurgling dribbling at the hose bib may be another clue indicating a waterlogged pressure tank.

How to recognize a waterlogged pressure tank and diagnose a short cycling well pump

Under the article named

WATER PUMP REPAIR GUIDE (links at the ARTICLE INDEX the bottom of this article ) beginning with the article titled SHORT CYCLING WATER PUMP, you'll see some articles on the causes and cure of short cycling on-and-off of the water pump, which is usually the explanation for water pressure surging and pulsing as you describe.

One cause of the rapid pressure drop you are citing ("it goes down to 40 in about 7 seconds") is a waterlogged water pressure tank - a tank that has lost its air charge - which may be why you're reading this article. The air in the water pressure tank acts as a giant spring to smooth the delivery of water to the plumbing system. When the air is lost or the air volume is too small, there's no spring. Because water is not very compressible, the pump comes on, rapidly reaches cutoff pressure, then cuts off. A result is rapid cycling on and off of the pump, and pulsing water pressure in the building.

Three methods for fixing a waterlogged pressure tank:

You're on this same investigation path, but it sounds as if you did not successfully add air to the tank. Just draining out some water, especially at first, is just draining out water that was under pressure. You need to get air into the tank using one of the methods we describe in this article (above). See these procedures for adding air at the water pressure tank:

WATER TANK AIR VOLUME CONTROLS

WATER TANK AIR ADD AT AIR VALVE

WATER TANK AIR ADD BY DRAINING

Also you might need to take a look at

WATER TANK AIR HOW MUCH TO ADD

WATER TANK AIR HOW OFTEN TO ADD

I've also seen this rapidly short-cycling water pump symptom when a water filter on the system is clogged or dirty.

Because the well pump can't force water through the filter fast enough to keep up with flow in the building, it can cause the pump to cycle on and off quickly, causing water pressure to behave similarly.

Of course there could be other causes, so after you've read the articles I've suggested,

1. post a comment or question here if you have specific questions that remain

2. let us know what you find, as what you learn will help other readers.

Reader Follow-Up: short cycling well pump fixed by adding air at the pressure tank

I can't thank you enough for your website and quick response! I wanted to write you back and let you know the outcome of my little well issue.

The surging water I described appears to have been caused by what you describe as “Well pump short cycling.” After reading (more carefully) your article: Well Pump Short Cycling: How to diagnose “Water Pump Short Cycling” and restore Air in a Building Water Tank

[see this article at SHORT CYCLING WATER PUMP] and your response,

I was hopeful that the cause was a waterlogged tank. I read your step by step instructions and it worked beautifully.

Opening up nearby hose bibs and the schrader valve helped the water drain more quickly, but it still took several hours to drain the tank.

Before I tried this, the tank was draining so slowly and gurgling, I didn’t think it was still full of water. It has been nearly a week the well is working perfectly now. Not only did you save me some money, but more importantly, fixing it myself was good for my self esteem. Thanks again!

Comment-DF:

Max, reading over your notes I add the observation that your 220 gallon water tank is larger than common in-building residential tanks (30-50 gallons) and may be an indicator that your well itself has a limited flow rate or water delivery capacity.

When we have a well of limited flow, a solution (other than drilling a new well) is to install a very large water storage tank and allow the pump to fill the tank at a slow rate that doesn't exceed the flow rate of the well. That assures the building always has plenty of water.

A worry, however, is that the slower the flow rate of a well, the higher the risk that it eventually stops completely. If you should need to investigate the well flow rate further, take a look at

WELL FLOW RATE or the well flow rate test procedures

at WELL FLOW TEST PROCEDURE and

see WELL YIELD IMPROVEMENT for help in increasing the well yield or flow rate. These and related articles are found at the ARTICLE INDEX the bottom of this article

under WELLS CISTERNS & SPRINGS