DIY Home Improvement Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
I have a couple of North American Boilers from 1963! One of the expanion tanks is full of air. I don't think the valve that adds air to the tank is leaking. I think it might be the Airtrol Tank fitting! Can this fitting cause the tank to be full of air? I have releaved the air and it comes back over night. I don't know how many gallons the tank is but it's about 3' by 8' and has a site glass that empty. The other tank is working fine. This is an Ohio school building.
 

·
Administrator
Joined
·
41,937 Posts
Stop leaving the air out. And look for a water leak somewhere in the system.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
Water leak

I think I would have a problem with both expanion tanks wouldn't I? I had a small leak at a dielectric coupling over the winter that I fixed by tighting it up. I don't think it's possible to have a system leak without knowing it at our building. Air leak yes but water leak no.
 

·
Administrator
Joined
·
41,937 Posts
Depends on the piping set up. One tank only can catch the air from the system.

After you leave the air out, and water comes back into the tank. That water is being pushed back out in to the system. Since an air leak in the tank, would cause the tank to fill with water. What is the water level in the other tank.

Can you post pics of the tanks and the piping to them.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
you would need a video

Each tank has a line coming out of the boiler return lines near the top front of the boilers. Through an air check and over to the Airtrol Fitting then into the bottom of the expanion tank. The line looks to be 1". I'm now wondering if that air check could be the problem.
The othe tank on the system from boiler number 2 has a water level right in the center of the site tube where it should be.
No way that big expanion tank has a hole in. It's sitting up in the air in the boiler room near my desk. I would hear or see something.
 

·
Administrator
Joined
·
41,937 Posts
Leak could be any where in the system. Do both boilers fire at the same time. Or is the second boiler a second stage boiler that only fires when its X cold outside?

The air check, shouldn't be able to let air in as long as the system has pressure in it. Unless the pressure is varying greatly.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
boilers

Both boilers will work at the same time or by them selfs. I have never tried both pumps at the same time. Each tank seems to be married to a boiler. The two pumps are not.
 

·
Administrator
Joined
·
41,937 Posts
Run both pumps and see what happens.
 
1 - 8 of 8 Posts
Top