Why does my hot water smell like wood smoke?
Okay, I needed to replace some damaged caulking in this shower stall, and this smell disappeared right after.

I'm thinking some mold (or mildew, or any other fun guys that like to grow in shower stalls) gave off this smell when heated.

As to why this needed re-caulking: I turn the shower to "hot" and turn it away from the shower stall door, towards the inside (cold water splashing on a person as soon as you wake up isn't Minnesota nice). This spray hits the vertical seam between two pieces of shower surround and eventually takes some caulking with it. Add this abuse up over several months and it's time to go to work.

Thanks for reading.