TOTO THU343 2-Inch by 4-Inch Outlet Assembly for In-Wall Tank System

Works as expected. It’s a second time I’m using this kit and works good!

The mounting bracket with this 2x4 conversion kit does not fit. After several calls to Toto and being told just push it harder, finally talked to a “senior” tech who said to use the bracket from the original 2x6 discharge on the 2x4 pipe. This was just one of many installation issues. Nice fancy product but you are going to really piss off your plumber with this one.

It's the part exactly that I want, it fits into two by four studs.

Actually ended up not needed this kit but did not realize until after the return period... - so if anybody is interested I will sell at a discount. PM me if anybody is interested

Worked out well ,and the price was right.

received on time and installed as expected. No issues.

Toilets with in-wall tanks and wall-hung bowls are popular in Europe, but very uncommon in the USA. They are cheaper in Europe. At this moment, the German Amazon sells at 248.80 Euro ($314.16) delivered, a complete brand-name Geberit system with 1) in-wall tank system, 2) ceramic bowl, 3) push-button plate, and 4) soft-close seat. In the USA, it would cost well over twice that. Of course, the average house size in Germany is half that of the USA, and their bathrooms are smaller. In the USA, the only reason to use one of these toilets, aside from prestige or appearance, is because of their small size within the room. Basically, somebody has a severe space problem. Installation requires some serious in-wall surgery. The tank system goes into the wall, and if you have a 2x4 wall, that is a problem. It is not the steel frame or the plastic tank that is the issue. The widest part, the tank, is 3-1/8 thick, and, when placed correctly, with the face of the steel frame flush with the studs, will fit comfortably into a standard 2x4 wall with 3-1/2 inch studs. The problem is the "3-inch" (actually it measures about 3-1/2) plastic waste elbow out the back. It projects to 3-3/4 inch. And even the thinnest no-hub coupling, used to tie into a 3 inch plastic or iron waste system, will add 1/8 inch. Total projection, 3-7/8, is 3/8 inch oversize for a 2x4 wall. Unless the installation is for old work with true 4 inch studs, or there is another workaround, this will not work. Folks at Toto have a solution, but it is pure Rube Goldberg. A substitute smaller and off-size diameter elbow and attachment clip replaces the 3 inch standard elbow and clip. Elbow true measurements are i.d. just under 2-3/4, o.d. is 2-7/8, and projection is 3-3/8. Space problem solved. Well, sort of. Just exactly what waste pipe size is 2-7/8? Included in this adapter kit is Fernco coupling 1060-22 which is "plastic socket size" for 2 inch pipe. This fits the off-size elbow. The other end of the Fernco coupling attaches to a custom plastic adapter. The other end of the adapter presses INSIDE a standard 3 inch plastic drain pipe. Not what you would call a straightforward approach. If you really need this adapter kit, you probably do not have much choice. But if there is a better way to incorporate the standard 3 inch waste, that would be better. The kit seems a little pricey for a Fernco coupling and three pieces of tough plastic.

This kit is absolutely mandatory when installing the in-wall tank unit in a 2x4 wall. The instructions for the tank unit itself don't describe this kit. The tank unit is designed for 2x6 walls. And the instructions for the tank unit don't really mention the 2x6 framing. This kit has a complete set of alternate instructions for 2x4 walls. A couple of cautions: 1. One end of the plastic adapter in this kit will fit inside the 3" PVC drain. Drain PVC isn't really designed for internal connections. They are typically connected on the outside circumference of the pipe. There is no standard for the inside dimensions of the 3" PVC. There is for the outside. So make sure to test fit the adapter carefully. The adapter may fit into one piece of pipe and not fit into another. Be really careful if using the cellular core PVC. 2. The folks at Toto support aren't really familiar with the in wall tank unit. It took me four calls to Toto before I found someone who knew that I needed the THU343 kit. 3. I doubt that you'd find this Fernco coupling at most big box stores. This is a plastic-to-plastic coupling. The one in a plumbing department (at least in the USA) are going to be PVC-to-PVC.