Water Tank Pressure Gauge FAQs

Water Pressure Gauge Installation or Replacement Procedure Q&A

Review my 6 Steps in Replacing a Water Pressure Gauge

My BII pressure gauge indicator on my home well pressure tank looks like it went bad. Everything else looks to be OK at the moment. Right now, I am looking to replace the gauge indicator. I was reading the "how to guide" above and had some concerns about what to do to fix this without calling a professional.

I will be buying the exact replacement part but the order of how to fix it confuses me.

1. I will turn off the power to the well.

2. drain the water from the tank out the bottom.

3. prep the new gauge for install with Teflon tape.

4. remove the old gauge.

5. replace with the new one. 6. turn power back on and refill the tank with water.

Is there anything I am missing or anything that I should be aware of or avoid. I don't want to screw the system up. Will I be allowing air into the system by doing this and if so what do I do? (Jan 5, 2015) Justin R.

Reply:

Justin,

Just how much trouble you need to go to depends on just where the pressure gauge is mounted.

Basically you need to turn off the pump, remove water pressure from the system, and if you don't want to get wet, drain water from the system or from the pressure tank to allow removal of the old gauge and installation of the new one.

Your 6 steps are just what I'd do. IF you're not going to mind a little splashing or water leakage, you can do this repair just removing pressure from the system but without having to drain all of the water out. Just don't panic when you remove the old gauge and install the new one when some water squirts out of the mounting tapping.

It helps to have an assistant to stand by to hand you the new prepped gauge.

I would take some care to avoid getting electrical components wet - protect them as needed. And mop up any spills so as not to be standing in water when turning the system back on.

And don't panic about squirting water such that you screw the new gauge in crookedly - if you cross-thread the receiving tapping you'll have created a bigger repair.

Take some photos of your procedure and send them along to me if you can - use the email at our CONACT link found at page top or bottom.

Good luck - let us know how you did.

Where to Mount the Water Pressure Gauge Q&A

Where do I install the water pressure gauge?

I need to know where to put my pressure gauge I have a new one on the tank it cut off at 60 then drops to 40 stays there until I cut the water on, it drops all the way to zero before the pump comes back on.

I may need to replace the pressure switch so while I'm at it do I need to move the gauge or add one? On 2015-04-27 by Lincoln

Answer by (mod)

Lincoln

Normally we'd mount a replacement gauge exactly where the old one was mounted.

Your old gauge would usually mount on or close to the water pump and tank or at a tank tee (photo shown here).

Look at the various photos on this page and at WATER TANK PRESSURE GAUGE to see typical water pressure gauge mounting locations.

Moving the gauge won't improve its performance. - Daniel F

 

Does the pressure control switch have to be on the pressure tank tee or can it be on the pump itself?

Our well pump (about 4 years old) has a pressure switch on it. We are now putting in a new tank and every piece of info we can find talks about putting a pressure switch on the tank T-fitting. Do we need to do that, if we already have the one on the pump?

Does the existing one on the pump take the place of the one that is always shown on the tank T-fitting? Or do we need to remove the one on the pump (plug it) and add one to the T-fitting? Thanks! Anon 2020-08-22

Reply by (mod) - where does the pump pressure control switch go?

The pressure control needs to be near the pressure tank or pump but it doesn't have to be at the tank if it's already connected on the pump itself.

Your original setup that had the pressure control switch right on the pump is fine.

In your new set-up, IF you were installing also a new pump and pressure control switch it would be fine to put the pressure gauge on the tank Tee provided that the pump was quite close by.

But if you are only replacing the pressure tank, leave the pressure control switch where it is: mounted on the pump.

That's fine. Daniel F. On 2020-08-22 by Heather

 

Above: A pressure control switch mounted on a 2 line jet pump/

Below: A pressure control switch mounted on the tank tee at a home in Two Harbors, Minnesota.

Water Pressure Gauge is Stuck or Does Not Show Water Pressure Properly FAQs

Pressure relief valve leaks and the water pressure gauge is stuck between 30 and 40 psi: should I replace the gauge?

My well ran dry and since has lost pressure, is short cycling and the pressure gauge is at a constant 32psi.

When I primed the pump the gauge read 0 and I watched it pressurize up to 32 but that was the only time it has moved. Any idea what the problem could be. Before this happened I had decent pressure but now I can't take a shower! please help. On 2017-11-08 by Mike

Initial Suggestions by (mod) -

From your note I can only guess since I have incomplete information, but there may be two problems here.

First, short cycling well pumps are usually caused by a pressure tank that has lost its air charge or has a too-small air charge.

W. If a pump does not turn on at all and if you don't suspect a problem with the pressure control switch, it's possible that you said a pressure tank air charge at a pressure above the pumps cut in pressure number.

Those two possibilities, of course, are two completely different issues with a water pressure tank.

Only one of them will be correct at a given time

Followup from Mike:

I've replaced relief valve on well tank 3 times. It still leaks.

I noticed pressure gauge is stuck on 30-40 psi.

Is a bad pressure gauge causing the relief valve to go bad? Would replacing pressure gauge fix the problem? On 2017-11-15 by MikeE

Diagnosis & Repair Advice by (mod) - Your water system is unsafe; no the pressure gauge doesn't affect the relief valve. Here's what's wrong:

Mike

When you have to keep replacing the same part I agree that something's wrong. What's happening? Most likely when you ran the well dry that also managed to pick up sediment, mud, dirt, debris from the well bottom that in turn would easily clog a pressure control switch and pressure gauge.

Watch out: If the relief valve is leaking (which I'm guessing is the case) then the problem may not be the valve but rather an over-pressure (and unsafe) condition in the water tank, perhaps because of a debris clogged pressure control switch.

If the pressure switch is clogged it won't respond properly to changes in water pressure. The risk, then, is that the pump keeps running past the CUT-OUT pressure, thus over-pressurizing the water tank.

The risk is that the tank explodes or bursts, injuring or even killing someone close by (that happened to a plumber in New Paltz, New York) and flooding the building.

That same debris can also clog a pressure gauge.

No replacing a pressure gauge won't fix any operating problem on a water system. The gauge is passive: it just tells us what pressure it's seeing. It doesn't talk to the controls, it doesn't do anything except tell us the pressure.

Replace the pressure control switch with a new 20/40 CUT-IN / CUT-OUT or similar pressure control switch AND clean or replace the small tube that conducts water pressure to the gauge.

And replace that clogged pressure gauge too. Then you should see your pump operate normally and you should not see leaking at the pressure relief valve.

Water pressure gauge doesn't seem to indicate correctly

I replaced the pressure switch, but the gauge doesn't show pressure building up; yet water came out when I got the gage off to prime the pump.

How long is it safe to leave the well running, and how do I check the water pressure gage.

It's a 40 60 pressure switch, can't afford a gage lost my home car truck everything And waiting on FEMA for help in a 8×22' travel trailer behind my 3500 square foot home

Isn't it supposed to show it bldg pressure I've replaced the pressure switch before if water is coming out do I still need to prime it I lost my husband 5 years ago after 40years but helped work on it before - On 2018-08-12 by Shirley

by (mod) - it's easy to make an independent test of water pressure using a hose-connection pressure gauge

Pressure switches are on-off controls. They do not include a pressure gauge that actually displays the system water pressure.

If you need to see the water pressure in your system, a water pressure gauge that simply attaches to a nearby hose bibb (outdoor faucet) or washing machine hookup can give you that information with no plumbing work whatsoever. The gauge itself costs less than $6.00.

I'll show one here - gauges like this are at hardware stores, plumbing supplier, and are sold online.

Details are at WATER PRESSURE MEASUREMENT

Diagnostics for a water pressure gauge that is not working are

at WATER TANK PRESSURE GAUGE

and detail

at WATER PRESSURE GAUGE ACCURACY

 

Water pressure gauge reading never changes - stuck at 30 psi

Replaced well tank pressure gauge and it is still always reading 30psi. Kicks on and off like normal but the gauge never moves. On 2019-04-10 by Lee b

Diagnosis by (mod) -

Lee

I suspect your water pressure gauge is "stuck" perhaps because the tiny orifice through which water pressure is allowed to enter the gauge is clogged with rust or debris.

You should try just replacing the gauge. Also see the two water pressure gauge articles shown in my answer for Shirley just above.

My water pressure gauge reads below zero: where do I start to fix this and do I need a whole new water tank ?

The gauge that is attached to my well water tank is reading below zero where do I begin to check is it the gauge that's broken or does this mean I need a whole new water tank system for my well ? On 2017-05-30 by Mary Collette Brandt

Diagnostic starting point by (mod) -

Mary,

If you have normal water pressure in your home then only the pressure gauge has failed and it needs to be replaced. I

A water pressure gauge is a standard part selling for between $5.00 and $12.00 U.S. and is widely available from plumbing supply houses and building suppliers and also online vendors.

I replaced the pressure gauge but still it reads zero: no pressure even when the pump runs and we have water pressure

I just replaced my pressure gauge and for some reason not getting any reading. Yes the pump has been turned back on and pressure built up .

I also blew out the port to make sure it was clear of any build up. I did check the gauge with an air line and the gauge worked . Faulty gauge ? On 2018-09-06 by Steve

Diagnosis by (mod) - two likely explanations

Steve

Two common explanations

One is clogging the sensor port on a gauge or on a small diameter pipe bringing pressure

Two, the gauge is mounted on a pressure tank and water is not entering the tank.

by Steve - it was a mineral deposit clog in the pressure sensor tube

I found the problem! When I took of the pressure gauge there was a calcium obstruction in the pipe .

Gave it a little tap with an awl and it came clean. It was amazing how much pressure was still there even with the tank drained.

Make sure you have the power off (I did), there was quite a jet of water that came up once the obstruction was moved.

by (mod) - Steve found mineral scale obstructing water pressure gauge pipe

Thanks for the follow up, that will help other readers. I'm glad to hear that you were successful.

 

Should water pressure and air pressure in the tank be the same?

Is it correct to say that the pressure gauge that is part of the system and an external gauge applied to the air valve on the pressure tank should read the same pressure? If they do differ, is that an indication that one or both gauges are faulty or is there some other possible cause? On 2018-05-30 by John

by (mod) - yes

Yes, excepting some odd cases such as a shut-off valve or obstruction between the pressure tank and the rest of the building water piping system where you're taking the measurement.

Consider that water in the system is entering the water pressure tank and there compresses air in the upper part of the tank. The air pressure and water pressure are in contact and will be the same.

Water in the Water Pressure Gauge - Leaks

Why would water leak into the water pressure gauge face/body?

What might cause water to go in an AVC pressure gauge?

We just replaced our AVC and got a new pressure gauge, turned power to the pump on and as it was building pressure water was going in pressure site. On 2018-04-20 by Gary

by (mod) -

Pressure gauges typically use a membrane or a thin walled brass tube as pressure sensor. That device can develop a leak, sending water into the gauge body where water shows up visibly in the gauge glass - and usually the gauge begins to leak.

Should I see liquid (water?) in the water pressure gauge?

Does a pressure gauge for a bladder well tank suppose to have liquid in it ? On 2016-12-21 by Anonymous

by (mod) - no, you gauge has failed and should be replaced.

No indeed, Anon.

If the tank gauge has water in it the gauge is leaking.

Watch out: You want to replace it as soon as possible since the risk is that the gauge bursts and the leak floods the building.

My replacement pressure gauge filled with water just like the old one

I just had a pressure gauge replaced because the old one had filled with water.

About 3 days after the new one was installed (by a plumber) it filled with water. Could you tell me what is causing this? thanks for any help. On 2016-10-20 by Darren

by (mod): take care to install the new water pressure gauge properly

I don't know but I suspect the new gauge was either defective or more likely was damaged during installation.

Watch out: one of the most-common mistakes, so common that pressure gauge manufacturers warn about it is installing a gauge by holding on to and twisting the gauge body instead of using a wrench on the gauge base. Don't do that, it breaks the gauge and can cause the leak that you have described.

No water pressure and air is blowing out of my water pressure gauge

My pressure gage that goes into my water tank reads zero and air is blowing out the bottom of the gauge hardly any water pressure in house On 2016-05-06 by Mike Carey

by (mod)

Doesn't sound good, Mike.

I trust you turned everything off.

Nothing should be coming out of the pressure gauge; if air or water is leaking out of the gauge it's broken and needs replacement.

If your gauge is mounted on a tank tee and the water pump is not working the pressure tank's air charge may be leaking backwards out of a broken or damaged water pressure gauge.

My water tank pressure gauge is dripping and there's water behind the glass. What do I do?

My water tank pressure gauge is leaking. There is a slow drip from the gauge and humidity behind the glass. What should I do? I just ordered a new gauge.

Do I need to exchange it? Can I just screw the current one on tighter? If I remove it, will water spout out? Thank you. On 2015-12-01 by Christine

Repair advice by (mod)

Christine:

Watch out: I would not touch the gauge until you are ready to replace it - though if the leak suddenly gets bad you'll have to turn off the water supply. My concern is that if you break the gauge body the leak may change from a slow drip to a fountain.

Replace the gauge as we describe at WATER PRESSURE GAUGE REPLACEMENT or REPAIR.

With the new gauge ready to install ( threads taped or coated with pipe dope) turn off the water supply and remove water pressure from the system so you don't get soaked. If you keep cool you do not have to drain all water out of the system.