caroma new construction installation question

We're investigating purchasing Caroma dual flush toilets for our new house but after reading the literature and installation instructions I'm a bit confused. The literature describes them as having a "full 4" trapway" and the installation instructions explain that "reducing wax rings must not be used!" We have roughed in our ABS waste pipes at a standard 12" from the finished wall but they are 3" diameter pipes.

Does this mean that I can't use one of these toilets? If I can't, are there any dual flush toilets I can use? What is a "reducing wax ring"?

Your pipe will work. It sounds like they advise against using these:



See how it tapers¿

You willl have a 4"x3" closet flange then.
It will still work with a 4" wax.


Caroma Sydney with 270 bowl.

Always avoid those rings like Kingsotall pictured. They are the ones with a plastic funnel on one side. The really mess up a 3" flange. Stay with a basic ring.