Water Tank Air FAQs

About the air charge in a water pressure tank

Water Pump Turns On Immediately - No Air in Pressure Tank?

Why does my well pump turn on the second I open any water tap?

My well pump cuts in as so as i turn a tap on. Why? On 2018-02-19 by Gerard

by (mod) - no air charge = waterlogged pressure tank so pump turns on immediately

Probably your water pressure tank is waterlogged, that is, it has lost its air charge.

See the repair procedure

at WATER TANK AIR, HOW TO ADD

Why does our Water Pressure Booster Pump Turn On Immediately when we Run Water?

We have a Davey HS18-30 booster pump with a small water pressure tank (2 gal?). The pump was in the house when we moved in, so I assume it was installed in 2004 when the house was built.

When running "normally" it comes on almost immediately when the water (any faucet) is opened, runs the entire time water is being drawn, then shuts off ~1sec after the faucet is closed. Is this the expected behavior?

However, on occasion the pump will run continuously while no water is being drawn. There are no leaks (running toilets, etc) in the system, but the pump will not shut off until we kill power to the pump and it will immediately start to run again when power is supplied.

We turn the pump off as soon as we realize this occurring but we have sometimes come home and find the pump has been running for hours (it's very hot and has heated the water in the pipes).

Eventually it returns to the "normal" operation described above. I'd like to figure out why this is occurring and if it is repairable or if this has potentially damaged the pump enough to warrant a replacement. On 2020-11-12 by Cameron

by danjoefriedman (mod) - For a Tankless Pressure Pump that's normal

Cameron

Some water pressure or booster pumps use an internal pressure sensor and are intended to turn on immediately when you open a tap.

Here's the DAVEY HS-SERIES DYNAFLO PUMP MANUAL [PDF] (at the Davey Water Website) - local copy saved as Davey-HS-Pump-Manual.pdf

For other readers in Australia or New Zealand, if you have a Davey HP.T or HS/T series pump, see this

DAVEY HP/T-HS/T WATER PRESSURE SYSTEM PUMP MANUAL [PDF] (at a New Zealand Pump Dealer Website) - local copy saved as Davey-HP-Pump-Manual.pdf

You'll see that Davey as well as municipal water system regulations all recommend an isolation tank between the main water supply and the pump. That's probably the purpose of the small water pressure tank you cite.

But the instructions say nothing about the pressure tank air pre-charge.

I think that it is normal for this pump to turn on immediately when you open a tap, as the little water tank you mention is an isolation tank, not a typical water pressure tank.

How to Drain a Water Pressure Tank that has No Drain Valve

How do I drain the Water Tank if there's No Tank Drain?

How can I let water out of a water tank that has no drain? On 2016-06-23 by walt

by (mod) - working on water tanks & pipes when there is no shutoff and no water tank drain

The water pressure tank will have piping connected to it.

That piping either goes to a tank tee that includes a drain valve, or you can install one by turning off the pump, draining pressure from the system, then cutting the pipe.

In the worst case I'd find the lowest and/or nearest outdoor faucet or hose bibb, hook up a pony pump using a washing machine hose to connect the pump to the faucet, then wiuth the pump electrical power turned OFF, I'd open one or more indoor faucets to let air into the system, the run the pump to draw all of the water out of the system.

If necessary there are freeze fittings or other devices that let us work on water pipes without draining the system. Let me know if you need help finding one of these.

See water tank draining step by step details found at WATER TANK DRAIN VALVE 

More suggestions that might help you are at ADD AIR to a BURIED WATER PRESSURE TANK - ideas on how

Can't Add Air to the Water Pressure Tank Q&A

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

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

Reply:

No George, but 38 psi sounds a bit high unless the pump control CUT-IN pressure is 40 psi - which would be the case if your pump pressure control switch is intended to turn ON at 40 psi and OFF at 60 psi.

 

I can't get air into my water pressure tanks

I have two hydro-pneumatic galvanized tanks that are over 50 years old, connected to a well for irrigation.

I've recently replaced the well pump, and the system worked well (cycling from 40 to 60 psi) for a couple of months.

However, now, after mild use this spring checking the stations, I can no longer manually air-charge the system to the recommended 20 psi (before I could but it took a very long time), and the pump will not cycle on although the tank pressure = 0!

Should I just change out the pressure switch or do I need to replace the tanks? Any suggestions greatly appreciated. On 2022-05-06 by Marvin

First steps by Inspectapedia Com Moderator

@Marvin,

Let's base our decision on objective facts: we need to understand "why" you can't correct the air charge in your pressure tanks: is there a bad air valve such as a jammed valve pin assembly or dirt or crud in the air valve inlet, or might your tanks have stuck air or water tank bladder, (if your pressure tanks use an internal bladder), or something else?

by Marvin

@Inspectapedia Com Moderator, These are hydropneumatic tanks that don't have bladders to get stuck.

by Inspectapedia Com Moderator - check the Schrader valve air inlet for damage or clogging

@Marvin,

Still I'd look for a blockage at the air inlet. After all, if by "can't air-charge the system" you mean you cannot introduce air into the tank and if you've already tried replacing the Schrader valve stem, then there must be a rust or crud blockage.

by Marvin - Air inlet valve not blocked

@Inspectapedia Com Moderator, Thanks for your replies!

I replaced the Schraeder valve core, and then probbed its internal plumbing for several feet with a wire.

I didn't feel any obstruction.

Unfortunately, I'm still not able to pressurize the tank after 5+ minutes pumping with electric auto tire pump. Not even a little, although air seems to be readily blowing through the tank's drain faucet when I open it.

by Inspectapedia Com Moderator - check for a debris clogged pressure gauge

@Marvin,

Is it possible that in fact you are indeed adding air to the tank but the pressure gauge itself is clogged and not registering?

by Marvin

@Inspectapedia Com Moderator, Its possible. i'll replace the gauge next. Thanks for the suggestion.

by Marvin - I was able to pump air into the tanks

@Inspectapedia Com Moderator,

Today my well people found that the brand-new pump is cycling on/off too quickly (Q 45 sec), causing the capacitors in the new control box to over heat and shut down the high capacity pump.

I was able to air-charge both tanks today to the recommended 20psi, which improved the cycle time but only to about 1-1/2 minutes, with tank refill taking another minute.

The pump contractor thinks that the tanks need to be replaced with 120gal bladder models for $3K apiece. (BTW turns out my tanks were placed in service in 1959!). Does this make sense?

I forgot to mention, that even after the improvement in cycle time following air charging, the pump still shuts down before getting through all six irrigation stations.

by Inspectapedia Com Moderator - check the air pre-charge pressure to be sure it's 2 psi below the pump CUT-IN

@Marvin,

The pump may be shutting down because it's overheating or because there is a pump protection device that is protecting it from damage when it starts pumping air rather than water.

But also I wanted to ask how you came up with the 20 psi air pre-charge. The water tank air pre-charge needs to be 2 PSI below the pump cut in pressure setting.

Water Pump Runs From Time to Time For No Reason

We hear a loud THUD and SPROING noise from water system - we were not running any water

City girl moved to country. I'm a newbie with well water systems. I was 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. (Mar 8, 2016) yvonne

Reply:

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 'sproing - thud' 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.

See our detailed help given at WATER PUMP NOISE DIAGNOSIS

Also see WATER HAMMER NOISE DIAGNOSE & CURE

Also, as you were awakened by this pump noise we must ask "Who or What was Using Water?" at that moment.

For example if you have a water softener that was set to regenerate at night, that would use water while you're sleeping.

But if there is no such equipment in your home and water is running, then there's a leak somewhere. For the diagnosis and repair of that problem

see WATER PUMP INTERMITTENT CYCLING

My pump goes on for a few seconds when no water is being taken from faucets etc.

I have a house pressure pump system, the motor and pump sits on top of the tank as a combined unit.

My pump goes on for a few seconds when no water is being taken from faucets etc.

I tried to inflate the bladder to pressure but it would not take air, I removed the valve and found that by inserting a small screwdriver into the valve tube, the rubber was hard up against the valve tube.

Does this mean that I have to empty the pressure tank before inflating? On 2018-10-11 by Alex -

by (mod) - Sometimes we can free a stuck bladder by BRIEFLY forcing the tank to a higher water pressure, but WATCH OUT

Alex

Nice going on the diagnosis of the water tank problem.

It sounds to me as if the bladder has collapsed and stuck against the tank bottom, preventing any water entry.

Sometimes we can free a stuck bladder by BRIEFLY forcing the tank to a higher water pressure, but

WATCH OUT: do not subject the tank to a higher pressure than its rating or the tank or nearby piping could explode and injure or kill you - which would make cleaning up the water spill pretty minor in comparison.

When a pump runs and you are dead certain no water is being run in the building I suspect a leak in well piping or in the check valve or foot valve.

About a pump that cycles on briefly when you're not running water,

see the diagnosis and repair steps at WATER PUMP INTERMITTENT CYCLING 

Well pump kicks on for 6 seconds when I'm not using water - do I need a new pressure tank?

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? (June 5, 2016) Lisa

Reply:

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.

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.

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

Well Pump Rapid Cycling as Cut-Off Pressure is Reached

Pressure Switch Cycles On and Off Rapidly at End of Pump-On Cycle

Pump pressure switch switches on and off rapidly when high pressure is turning pump off On 2018-05-23 by Rob

by (mod) - problem of rapid water pump on-off cycling right at the CUT OUT pressure

Often I find that the problem of rapid water pump on-off cycling right at the CUT OUT pressure is traced to

- Most Often: a debris-clogged check valve between pump and well pipe bottom - pump stops, high pressure water squirts back into the well, pump re-starts. You can diagnose this by watching the water pressure gauge at pump cutout.

Try turning the pump OFF just as it's reaching the CUT OUT pressure, then watch the pressure gauge.

If it falls, and if no water is being used in the building (turn that valve off for this test) then there's a leak between pump and well pipe end.

- On occasion: a failing pressure switch: burned contacts,

- Often: debris-clogging at the switch pressure sensor port or in the tube bringing water pressure to the switch,

- Commonly: water leaks in the system, such as a bad check valve or foot valve, that shows up more severely at the higher pressure near the pump CUT OFF setting

- an obstruction anywhere between the pump and the pressure tank

- or a cut off pressure that is close to just what the pump can produce

- On occasion: improperly-located pressure control switch - too far from the pressure tank - if this is the case the problem may have always been there or it may show up on an older system in which for any reason the pump output capacity has changed

Details about these problems are

at WATER PUMP PRESSURE CONTROL SWITCH CHATTER 

Also review WATER PUMP SHORT CYCLING CAUSES

or if you prefer causes and cures in a more concise table see

WATER PUMP SHORT CYCLING DIAGNOSIS TABLE

If the pump turns on immediately when you open a tap your water pressure tank is water-logged - has lost its air charge, see WATER TANK AIR, HOW TO ADD

If the pump runs occasionally for no reason there's water running somewhere or there there's a leak - see WATER PUMP INTERMITTENT CYCLING

Well Pump Sometimes Cycles on and Off repeatedly at the end of a pump-on cycle, then stops.

By water pump seems to cycle properly while we're running water.

The proplem is "Some Times!!" at the end of the cycle as the pump cuts off it immediately restarts for a second or a couple seconds cuts off repeats then will cut off normally --- the water pressure is at the high point on the gauge when it gets to the lower cut on pressure it will cut on again,

but at the end of the run cycle it will the "chatter" or cut off as it should -- real problem is sometime the contacts are together (but don't conduct enough to start the run cycle then I have no pump and no water On 2012-07-18 by Anonymous

by (mod) - causes of a sudden repeat pump cycle right at the cut off point

Anon:

Two things (there are surely others) that cause a sudden repeat pump cycle right at the cut off point are

- burned pressure control contacts or a failing switch

- dirt or debris blocking the pressure sensor port at the switch base

From what you describe, I would replace the switch and make sure to also clean or replace the tubing or pipe nipple that conducts water pressure to the switch mounting base (that contains the pressure sensing port)

Jim:

It sounds to me as if there is a bad check valve in the pump or in the well, perhaps combined with a waterlogged pressure tank.

Jennifer: I'm not so sure of this one, partly we need to know how the well and water piping are routed; Usually a well pump feeds the building and simultaneously the pressure tank; If that's your case and you get no water at the house the problem is obviously before that point - a well piping leak, clog, valve problem.

If your water pressure tank is piped "in series" between the incoming water and water piping to the house such that water has to enter the tank before heading on to the house (an unusual setup) then you could have a stuck tank bladder that prevents water from entering the tank.

Air Charge in Pressure Tank Seems to Get Lost & Pump Short Cycles

Water Pump Short Cycles Again After I've Added Air to the Pressure Tank

Our water pump often short cycles. And whenever it does, I drain and refilled the tank. But these past few months, our water pump has been a problem.

I was doing the draining and refilling for an average of every 6 days. It does its job on fixing the cycles but after few days, the pump short cycles again. What might be the problem? On 2018-02-15 by Jose

by (mod) - water pressure tank rapidly loses air charge - find the leak

Jose,

If you're sure the tank is starting fully empty, air filled, and it loses it's air charge in a few days, and your water usage volume is typical, then I suspect the tank has an air leak, maybe high in the tank or at the air valve.

More diagnosis and repair advice is at WATER TANK AIR LOSS SIGNS

Water Pump Can't Reach CUT-OFF Pressure

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

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? (Nov 6, 2014) Brad Shoults

Reply:

Brad

It's possible that your water use rate is simply faster than the pump can deliver. We might particularly find this situation if your well is a very poor or low-flow-rate well and if your plumber installed a well piping tailpiece or other control to slow the pump's water uptake so that it won't drop the well water level so fast that the pump begins pumping air - a condition that can damage the pump itself.

We explain the use of well piping tailpiece pump protection devices at WELL PIPING TAIL PIECE 

If that is NOT your situation, then

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

Pump Control Switch

Water pump runs if I give the tank a little shake - is this a switch problem or an air pressure problem?

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? (June 15, 2016) Matt

Reply:

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.

 

Water Pump is late to start and late to stop - is it a bad pressure switch or a bad tank bladder?

The problem with my booster pump is different from what you have described above...what I am experiencing is that the pump is late to 'kick in' and also late to cut off. I had tried to adjust pressure switch cut in and cut off nuts but the issue still persists (coincidentally my pump is fitted with Square D FSG 2 Pressure switch).

What you think could be the issue? Is it my tank bladder or the pressure switch? On 2011-08-27 by Izhar

by (mod) - Probable cause: sediment-clogged pressure switch or switch tubing

Izhar,

When a water pump is not responding properly to the pressure in the system I suspect that the pressure control switch is defective OR (and this is very common) if there is rust, iron, sediment, crud in the water supply, the switch may no longer be sensing pressure in the plumbing system.

A blockage of the pressure switch mounting tube or the very small water orifice (hidden from your view) in the bottom of the pressure control switch sensing diaphraghm can cause the switch to delay starting in response to a drop in water pressure.

Other mechanical problems within the pressure control switch itself could be at fault too.

I'd replace the switch and the mounting tube.