Proper Support for Thermal Expansion Tank - InspectionNews

Bruce Ramsey · #1 (**permalink**) 05-01-2009, 08:53 AM

IRC 2903.4 requires the use of a thermal expasion tank. I am not able to find any verbiage about the proper secureing and support of said tank.

Almost every picture of a tank on this forum gets bashed for improper support. Yeah, I know it makes sense but is there some specific mention of how or a requirement to do so?

It is "not right" and "common sense" but I want to back up my claims with code or manufacturers instructions if I get in a discussion with the builder/plumber. Any pointers?

Scott Patterson · #2 (**permalink**) 05-01-2009, 09:17 AM

Quote:

Originally Posted by Bruce Ramsey

IRC 2903.4 requires the use of a thermal expasion tank. I am not able to find any verbiage about the proper secureing and support of said tank.

Almost every picture of a tank on this forum gets bashed for improper support. Yeah, I know it makes sense but is there some specific mention of how or a requirement to do so?

It is "not right" and "common sense" but I want to back up my claims with code or manufacturers instructions if I get in a discussion with the builder/plumber. Any pointers?

With the copper pipe and as pictured I don't see the need for additional support. Most of what I'm seeing now are PEX pipe with dangling expansion tanks, those need support.

Jerry Peck · #3 (**permalink**) 05-01-2009, 09:24 AM

As Scott said, with copper pipe and being mounted vertically above (or below) it ... that is the key.

When mounted off to one side, the weight of the tank and the water in the tank can break the fittings off and then additional support would be required, same goes for PEX systems - additional support would be required.

By the way, I am sure you already have this, but that insulation needs to be 6" or more from the draft hood.

The Watts installation instructions even shows it self-supported vertically above or below the rigid piping, and additionally supported when teed off other than vertically above or below: http://www.watts.com/pdf/1915356.pdf

Ron Hasil · #4 (**permalink**) 05-01-2009, 08:16 PM

That is the proper way with copper pipe. If it was plumbed to the side then additional support is needed. You can go by the manufactures instructions. Here is a PDF from Watts http://www.watts.com/pdf/1915356.pdf

Ron Hasil · #5 (**permalink**) 05-01-2009, 08:17 PM

Wow I just noticed Jerry already posted the link. Helps if I refresh my Cache.

Ron Hasil · #6 (**permalink**) 05-01-2009, 08:21 PM

Oh the water shut off is in the wrong spot. Most plumbing codes want the shut off to be before the the tank. This part is from the Illinois Plumbing Code.

C) A properly sized and approved expansion tank shall be located on the outlet side of the check valve in the water heater's cold water supply with no shut-off valve between the heater and expansion tank.