My gas hot water heater has been working problem-free for years until recently. I shut the water heater off because I was going to be away from home for a few weeks. When I came home and tried to relight it, the pilot light would not stay lit. I have replaced the thermocoupler and that didn't fix the problem. As I'm trying to light it, the pilot burns with a bright, blue flame, so I don't think there is a gas flow problem either. Any final suggestions before I bite the bullet and replace the hot water heater?