Pilot burner went out .we replaced the thermocouple .hot water tank worked fine for 2 hrs. pilot burner went out again .pilot burner will light but will not stay on.

You could have the thermocouple adjusted wrong. It must have a flame on 3/8" of tip only. Also, you could have a bad pilot holding coil in your gas valve. You will need to test it with a meter on mega-ohms scale. Where you screw in thermocouple the center is one terminal and the body of the gas valve is ground. Test between the two points. If it reads infinity get a new valve.

I have the same problem. Did you ever figure out what was wrong?

When you are trying to find out what the problem is that is causing a problem you need to learn to use a meter. It's simple and you will always be right if you use the meter properly. It sure saves you from guessing and changing out good parts for good parts and wasting time and money.

I know how to use a multimeter. I have a doctorate in Physics. The problem is that I don't understand what you are saying needs to be tested. I don't know what a pilot holding coil is. I really just wanted to find out what the person who actually had the problem did about it.

Hi David

That person is no longer around here so they can't help you. And, not to doubt you and your "doctorate in physics", but DrTom's answer was very clear about what the coil is and how to test it.

Tom said, "you could have a bad pilot holding coil in your gas valve"

Then he said, "You will need to test it with a meter on mega-ohms scale"

Then, "Where you screw in thermocouple the center is one terminal and the body of the gas valve is ground (other terminal)"

And finally, "Test between the two points. If it reads infinity get a new valve".

That a little clearer now?

Mark