My toilet flange (installed in an unfinished basement with a cement slab) seems to be just a solid surface. It does not appear to have any sort of knockout. It looks in every other way like a toilet flange, complete with the collar, holes for the bolts, etc. But instead of an indicated area to knock out, it is just a solid, smooth surface. There is a small cylindrical shape, about the size of a quarter, in the dead center. It looks like it might have been cut off, but I am not sure.

What do I do? Do I cut into it and hope that it has a hidden knockout, notched from the under side?

Do I somehow remove this to expose a pipe that is ready for a new flange? If so, why does it have the collar and holes that are identical to a flange?

Any help would be great. Thanks

I think you were sold a closet flange with a knockout. These are for blocking off the closet bend so we can fill our stacks for inspection. After inspection we knock them out. NOTE: Be careful none of the plastic falls down into the closet bend. If any does, fish it out. Good luck, Tom

I think you were sold a closet flange with a knockout. These are for blocking off the closet bend so we can fill our stacks for inspection. After inspection we knock them out. NOTE: Be careful none of the plastic falls down into the closet bend. If any does, fish it out. Good luck, Tom


Is there a reason why there is no indication where to knoack it out? All of the knockouts I have seen have a circle that indicates the opening.

Is there a reason why there is no indication where to knoack it out? All of the knockouts I have seen have a circle that indicates the opening.
Here's what one looks like,(see image) the ones that I've used just had a plastic membrane across the top that you knocked out. It would make no sense at all to produce a solid closet flange but if you're concerned and don't have to fill the stacks for a inspection why not simply exchange it? Good luck, Tom