Thanks again to everyone who offered plumber recommendations. As promised, here are all of the responses (in the order they arrived):

Al Bouman - 724 462 8456. He's come twice on time, courteous, free estimates and cheerful disposition. Also, he cleans up after repairs.

I've actually had good luck with RotoRooter. You always get a different person, but they are very knowledgeable. Also fairly priced, I think. Oh, you can get a sizable discount if you use a coupon from the phone book. I used someone else last time--Morrie Cohen. He comes quickly--no waiting--does the work, leaves without saying goodbye, no chit chat, but good and fairly reasonable as these things go.

We have had very good experience with B & F Plumbing, 412-682-7151. We've been using them for 20 years.

I've used R.J. Johanssen [check spelling] on Baum Blvd in the ~remote past, on recomm's from a few neighbors. Found them reliable, maybe a little expensive.

Ron McCarrison does our plumbing -- a truly nice guy who works on his own. He's based in Verona. I got his name from the original Highland Park list about 8 years ago (after a bad experience with Stahl Plumbing).

We have used Joe Hoffmann for nearly six years – fair, nice, honest. 412-921-8662

RDN Plumbing – Recommended by two people. Here was one of the responses: Try RDN Plumbing (412-462-1435). They're in West Homestead, but have several plumbers, one or two of whom focus on East End. About 8 months ago, I had a problem with a leaking shower faucet, that my prior plumber had told me could only be repaired by ripping out the wall and reinstalling the entire valve. RDN's guy came out, found the problem, had to go downtown to get a replacement part, but had the thing fixed in a total of about 4 hours. Price was reasonable, but not "cheap", and the wall did not need to be touched. He even alerted me to the risk that the other shower faucet could develop the same problem, showed me how to fix it myself and gave me info I needed to buy a backup valve core. One drawback to these guys--they do only plumbing, no heating or cooling system work.

I have used "M&D Plumbing" several times over the last ten years. You can call Marty Kralik at 412-741-2786. He has always returned my call the same day and did the needed repairs the next day. I think he's very reasonable for a plumber. They have done everything from a new hot water heater to leaking pipes. Highly recommended.

We are seriously in love with Richard Dodaro, whom we found on Angie's List. He has now done three different jobs for us, responded quickly and showed up reliably and we're about to use him for a major gut job/renovation on our master bathroom. His number is 412-243-1796 or 412-906-3772.