I have a back outlet, floor mount toilet, and I would like to install a wall-hung toilet instead. The waste riser is cast iron with 4" threaded opening, and my current toilet is connected to it with this ABS nipple...
The wall tube is 1-1/2" and the waste connector has a smaller inner diameter, so the waste arm won't slip into the stub.
Is there some kind of adapter I'm supposed to use?
Thanks!