I have a similar problem. I have two gas HW tanks, one no problem, the other pilot goes out every week or so for no reason. Relights okay, no problem. I've changed the thermocouple, as well as cleaned the outlet with a toothbrush strapped to a metal pole. Scrubbed any loose debris off, but still didn't fix the problem. I've also drained the tank, refilled, and still have the problem. I guess I'm in the same boat as the rest of you. DPSkiman@hotmail.com