Hello,

I replaced the tank around Dec of 2022 and now it's leaking water. The old one last about 10 years.
Is there any chance the tank is defective? But it's an Amtrol, a popular brand.

Here is how I checked. I tapped on the upper and lower part of the tank. The sound was similar and the lower part didn't sound empty; I used a tire pressure meter trying to test the air pressure but it was almost impossible to fit to the bottom aperture of the tank. But there was no water coming out of it.

I adjusted the boiler temperature to the lowest trying to keep down the pressure inside the boiler. Now the leaking is not as much as before.

I tried to contact the plumber since he was the one who bought the tank for me. i guess it should be still under warranty. Hopefully I can get a replacement.

I don't think it is the T&P valve leaking; it should be the tank, right? I need you guys' advice.

Thanks in advance.
John

 

z,
Your AMTROL TANK has a 5 yr. warranty. Your relief valve is doing it's job so forget about changing that.

Next, your tank is factory set to 12 psi so if it is full of water either the bladder has ruptured or was not properly set from the factory. Your tank must either be removed or isolated from the system to properly check the pressure with a tire pressure gauge.

When doing the tap test the top should sound solid and the bottom, hollow. If both sound solid the bladder has lost it's charge and must be recharged or replaced.

Hope this helps a little.

 

There was no water coming out of the new pressure tank but you let all the air out.

 

Thanks guys!

Are you saying that I can take off the tank and dump the water inside the tank; then recharge the air from the bottom valve with a compressor; then reinstall it?

Amtrol is a pretty popular brand for expansion tanks and it should last longer than 5-6 months.

after I installed the tank, the plumber increased the water pressure of the boiler to about 20 psi through adjusting the pressure reducing valve. Does that have anything to do with the tank turning bad? Or what caused the problems with the tank? My previous Amtrol tank last over 10 years.

Thanks again guys!

 

You do not have to remove the tank or drain it.

Reduce the system pressure to zero by draining just enough water from the boiler drain so the pressure gauge reads zero.

Pressurize the tank to 12 to 18 pounds through the Schrader (tire) valve with a compressor or tire pump. If the boiler drain is closed you may be able to see the pressure change on the boiler gauge. Depending the size of the system you may not and can use a tire gauge to read the pressure at the Schrader valve.

When the tank is pressurized use the incoming water pressure reducer valve to bring the system pressure back up to 12 pounds or to your normal system operating pressure (houses more than 2 stories may need more pressure.)

 

Running your system at 20 psi is fine and had nothing to do with your deflated bladder. How you get your pressure to zero depends on the valves on your system. You may have to bleed after refilling.

If unsure, pics of your system would help.

 

Thanks 2john2458, I will try you way at the weekend, and keep you posted. I tried to measure the pressure yesterday by screwing on the compressor valve to the Schrader valve. But the center part (or the tip) of the S-valve refused to recess so there is no way of measuring the air pressure at the lower part of the tank. Hope it's going to change after let out some water from the boiler.
Have a good one.

 

If no water at the air schrader the bladder is good. If possible isolate the the boiler from the system closing any valves on the heating supply and return pipes so as not to drain water from the system just the boiler.
As stated earlier the water pressure needs to be at "0".
Add air pressure to the tank, adding air will push water out. If you are going to run 20 PSI instead of the standard 12 psi you will have to add more air to get the tank pressure to 20 psi. The air charge in the tank must match the system fill pressure (within a few PSI) or you can prematurely fail the tank bladder.

 

Hello guys,

I partially drained the boiler today. Now the water pressure stays around 22 psi when it stops running. Based on what rbeck said, it’s higher than normal but it sounds acceptable.

Rbeck is right that the tank is not faulty because as I pump up air thru a tire compressor, there was no leaking water from the Schrader valve, even though it’s hard to screw on the compressor’s valve.

A couple of thing that I am not sure. 1) I kept the supply valve near the expansion tank open as I drained the boiler. Not sure if the water in the upper part of the tank can be drained also. 2) not sure how to reduce the air pressure of the tank because the Schrader valve is very hard to push in to let out some air.

 

If the supply valve is left open at the top of the tank and the air in the tank will push the water out. You cannot know the exact air pressure in the tank unless the valve is open and you drop the water pressure in the boiler to "0".
I would drop the pressure in the system to 12-15 PSI but 22 is OK, this would mean adjusting the water feeder when refilling the boiler.
How much pressure change is there from cold to hot boiler temps?

The cold fill air pressure should match the water fill pressure or the tank will pre-maturely fail.

 

If you close the ball valve before the amtrol that would isolate the tank and eliminate the boiler draining and everything else. After closing the valve just remove the tank and then check the charge and drain the tank if you want.

That schrader valve stem should be easy to push in just like on a car. If not then there is a problem. Check everything when tank is removed.

 

Rbeck,

As I closed the water supply valve and drained the boiler, the water pressure came down to zero almost right away. My question is, do I need to keep the ball valve closed as I drain the boiler?

The change in water pressure as the boiler temp changed from cold to hot was up but not much.

Spott,

That’s what I thought: if the ball valve left open, the water in the tank can be drained, or it cannot. That’s why I left it open. Again, the Schrader valve stem is real hard to push in; I screwed on the tire compressor’s valve using a plyer, unable to be done by hand

One thing that is weird: the boiler almost stop running after what I did. I suspected the boiler might have problems so I raised the temp to 80 degree. Then the boiler started running immediately. But as I checked the temp, it almost reached 70 degree (the lowest). In the last year, the boiler ran only twice in the weather like now during the day time. Now it’s almost zero time. What do you guys think? It’s definitely not normal.

Thank you both!

 

Btw, do you guys have any suspicion on the T&P valve?

 

Z,
A couple things about the schrader valve. These are just questions and nothing more. I have a feeling you are trying to push in the whole threaded housing of the schrader valve and not just the pin. Your tire gauge does not have any threads. It just pushes on.

Do you realize the threads on a schrader valve are just for the CAP and not the hose end of the pump. The other thing is on that schrader valve is a little metal pin in the middle of the valve that depresses easily when adding or removing air. You do not wind the pump onto the threads. They are not there for that reason. If you use a tire pressure gauge you just push it on and the middle piece of the gauge will depress the pin in the schrader valve to get a reading.

As far as your T&P valve goes. On your boiler is only a pressure relief valve which goes off at 30 psi. On your Indirect tank you have a T&P valve which is different. If your boiler relief valve is leaking it is most likely when your boiler reaches 30 psi because of your Amtrol tank problem.

If you close the ball valve and unscrew the tank you can tip it over and drain the water.

If that tank is in too tight a spot you can add on pipe and bring it to the front where it's easier to work on.

 

If you close the ball valve for the expansion tank and then remove the tank without first making sure there is zero pressure on the air side of the tank, there will be water shooting out from the tank! Ask me how I know, more than once...

 

Thanks spott for the update, and also thanks to poorplmbr for the reminder. But I need to make some corrections. Sorry that I gave you some misleading information.

I told you guys it was hard to screw on the compressor valve to the Schrader. I was wrong probably because the air pressure inside the tank was too high. I tried again yesterday and it was pretty easy to check the air pressure either with the compressor’s meter or a stand-alone meter (see the pic, the pressure now is about 12 psi; sorry that it is not a good pic). I also adjusted the pressure-reducing valve to make the water pressure about 12 psi, like what you guys told me to be consistent with the pressure of the tank.

The thread of the compressor valve matches the schrader’s (check the other pic please). It’s a Harbor Freight tire compressor. I think it’s better than a push-on valve because it has no leaks and it is probably more accurate.

I am sure you guys are right that the T&P valve has nothing to do with the water leaking. The leaking comes from the high air pressure of the tank. As I tested to increase the air pressure, there was more water dripping from the T&P valve; as I let out the air, the leaking was less, even stopped.