Expansion tank on side!

What do you guys think of this? I have only seen expansion tanks (with diaphram) installed vertically, not horizontally. In fact, I just installed a similiar tank myself and the directions indicated it should only be installed vertically. Also, the low water cut-off is on the return. When I installed mine, the directions indicated to put it on the supply line.

I tried to attach a photo but it wouldn’t attach. The system was a Utica boiler. Model number MGB100HD. Manufactured in 3/04.


Learn how to post pics with this Tutorial

I checked out the tutorial and I was trying to do it correctly but I keep getting a message indicating “The Page Cannot Be Displayed.”

Did this happen while you where doing the tutorial?

I just did it and it worked fine.

What type of connection do you have?

Hi Mike, Sorry took a while to get back to this. Haven’t been on lately. Yes, it did happen during the tutorial and after it. I use Verizon Fios as my provide for High Speed Connection but when I just tried to upload the picture again I got a different message saying the file is too large. (Its just a simple picture from a 7megapixel camera.)

Your are geting close Pat.

jpgs can’t be larger than 640 x 480

The other format sizes are also listed when you upload

After you have resized you pics I’m sure it will work just fine.



Looks like an Amtrol Extrol.

The EXTROL is installed on the supply-side of the boiler system. Its
sealed-in air pre-charge prevents water from entering the tank until the
system pressure begins to rise.

Installation Guide(PDF)

It should also be vertical as shown in the installation instructions.

Thanks Mike. That’s what I thought. I wrote it up as “an atypical installation that should be further evaluted by a licensed plumber”, rather than saying for certain that it was incorrect.

In my opinion, there is nothing wrong with that installation. Expansion tanks can be installed horizontally. The recommendation that they are installed vertically is to reduce stress on the (normally copper) pipe, which should be adequately supported even if the tank is suspended vertically.

They look like galvanised fittings which will support the weight, so what is the problem?

I agree…there is nothing wrong with that install. The stress put on the connector is minimal and the Bladder will work just fine.

So, the manfacturer’s instructions to mount vertically are unimportant?

Looks pretty strightforward to me:


Who reads those things??? Get rid of those things before the wife finds it and tells you how to do it. :stuck_out_tongue: :stuck_out_tongue:

Yep, me too:D

Fellow Inspectors,
I contacted armtrol and received this response:

Anatol, When installing expansion tanks, they should be VERTICAL. Horizontal installations have the potential to trap air inside the water chambers of the tanks and cause corrosion from within.

I guess that clears it up…
Ray Deming [rdeming@amtrol.com]