I recently improved one entire bathroon in a 30 y/o home (w/ 3 other bathrooms)--to include flooring. I removed the toilet, removed old wax ring & putty, put on a new wax ring, removed the toilet paper from the hole & reinstalled the same toilet--assuming everything was done correct. Now, when I flush the toilet it begins to flush, but then refills with water up to the rim. I figured it was an air bubble in the system from removing the toilet, so I flushed a second toilet in the home & now that toilet has the same problem, (but the other 2 toilets in the home are fine)--how can this plumbing problem be fixed?