Hi! I just moved into a very old (1929) Tudor in Michigan and, as part of my yearly maintenance, wanted to have the main sewer line cleaned out/inspected. (I have very large old trees in the front yard and am concerned about the roots.) The plumber who arrived yesterday could not find it -- he did locate (as did I) a large vertical pipe with a "Y" piece at the bottom (near the floor in the basement), but told me the existence of this "Y" configuration meant someone had placed the clean out somewhere else in the basement. After hours of searching, we found no clean-out. My questions are these: is it possible that this old house does not even have a clean out (the prior owner, who I called, did not even know what a clean out was... )? Second, if I don't have one, or just can't find it, can I access the sewer line some other way?

Would really appreciate any help on this one... thanks in advance to anyone with some insight on this frustrating problem.

Yes not having a clean out is very common, I have a home built in the 60's and it did not have a clean out when I bought it.

You can, as a lot of people do, go thought the vent pipe on the roof, remove a toilet and go though there. Or if you want it in the basement merely put one in on the main line in the basement

And if one side of the "Y" was open, that could have been the clean out if it went into the main sewer line.

Your plumber should have had a dozen suggestions on putting one in.