The pilot light on my water heater went out yesterday and I was able to get it going and had hot water for most of the day. But it went out again last night, and I was able to get the pilot light to relight when pressing the button but when let up on immediately goes out. I tried replacing the thermocoupler today, which most websites say to do in this situation, but after following closely the directions and pictures I found (and two different thermocouplers) I had no luck relighting the water heater. I am usually extremely handy around the house, especially in regards to plumbing, but I'm struggling with this. Please help! My wife and I would like a hot shower as soon as possible.

Brand and model number?

How old is the heater?