Copper Joint OK?

I have a question for the professionals. We built a house recently (but out of our plumbing warranty) and have a leak between our hot water heater and the expansion tank.

When I looked at it, it seems to me that the joint was messed up from the very beginning (and I'm hoping to get it honored by the warranty on those grounds).

The cold water line comes in horizontally and goes to a tee (but without a tee fitting). Up is to the bottom of the expansion tank. Down is too the hot water heater.

Why would that not be a soldered tee fitting? Is it ok for the expansion tank to be installed upside down like that? I've read that can allow air on the water side of the expansion tank? Does any of this work actually conform to the plumbing code in the Pittsburgh area?

Here are some pictures:

 

It's common to install the expansion tank upside down, it can be installed in any direction. The copper pipe looks like a prefabricated piece made specifically for the expansion tank, my first guess is that it is a manufacturers defect. There is no way to tell who's fault it is why it leaks. You could try to locate the manufacturer.

 

If the precharge is set correctly, there should not be opportunity for much air to collect as the tank would be completely emptied whenever a faucet is opened.

 

Thanks for your replies. I have a plumber coming tomorrow.

 

Id be disappointed and possibly complain but I wouldnt install thier junk again. I guess its just me but Id repair it free for my customer. 1 year warranty if its 2 years Id handle it much past that Id charge

 

https://www.siouxchief.com/products...fip-swivel-straight-adapter-w--expansion-tank looks like the failed part.




Different tank makers have different requirements. https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Amtrol-140N43-Install-Instructions.pdf says "Mount tank vertically in downward position only."

Watts https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Watts-0067370-Install-Instructions.pdf says

" The expansion tank may be installed vertically (preferred method)
or horizontally. Caution: The tank must be properly supported
in horizontal applications"​

 

Hadent seen those before Soix chief if manufacture of this particular piece is usually decent products. coulda been compromised by stress from original installer as well. easy fix though!

 

Since it's a prefab part, it looks like it's easy to replace. Everything just screws together without having to disassemble the pex or any copper. I'd just take the 15 minutes and replace the part and not worry about it.