A: Thanks for writing, Randy. I agree with your approach to fixing this problem. You did everything you could to the old toilet and when you ran out of options, you did not waste anymore time and you installed a new toilet.

I have seen homeowners and contractors waste days trying to fix broken fixtures to no avail. Good troubleshooting!

Now, back to your question. Since you could not find a clog in the old trap and the flushing system on the toilet was in working order, my theory is that your old toilet had lost the ability to create a siphon. When most toilets flush, they depend on the siphon jet hole (located at the base of the toilet bowl, just before the trap opening) to push out a heavy flow of water into the trap. This strong flow of water, combined with the jet flow velocity, creates a siphon in the trap and that siphonic action pulls the debris and water from the toilets bowl.

Yes, you heard right. When flushed, most toilets "pull" the water out of the bowl; contrary to popular belief it's usually not "pushed" out. If the siphon jet hole becomes blocked or broken, the trap can fail to produce a siphon and that may result in a flush that has no power.

Sometimes you may be able to clear or clean the jet hole, but in most cases when a toilet loses the ability to produce a siphon, in my opinion the best bet is to replace the toilet. Bottom line, you solved the problem and your clients are lucky to have a contractor that cares and is always looking to learn.

That should make you flush with pride!