I can light the pilot light and the burner will turn on. Once the water is fully heated, the burner turns off, the pilot light goes out and I am unable to keep the pilot light lit until the unit cools back down (after the pilot light goes out, I have to wait a couple of hours and use some of the heated water before I can light the pilot light again and have it stay lit). I have replaced the thermocouple and am still having the same issue. When the unit is cool, why will the pilot light stay lit and work correctly? Any ideas? Thanks for the help.

This type of problem is usually a bad thermocouple which is easy and quick to replace. Do you need help with the replacement?

Hi Limited...

I see that you already replaced the thermocouple (I think Bob missed that)... how did installation go?

You still have the same issue as before the replacement?

If you have the same issue as you started with after replacing the thermocouple then either you didn't install it properly (unlikely) or you could have some kind of combustion air makeup issue, OK?

To help me determine more could you please post the name of the water heater, the model number and the serial number on the water heater tag (near center front heater most of the time). If you know how old the unit is that would also be super helpful!

Back to you...

Mark

Duh, my bad , totally mised the replacement, disregard my first post.

It is a Kenmore. Model # 153.334452, Serial # A98119373, installed around 1997. I am pretty sure the thermocouple is installed OK. I have had to do the thermocouple before about 7 or so years ago and it worked fine then. Thanks.

LC...

You have an older model water heater with an open combustion chamber so make up air should not be an issue... UNLESS this is in an enclosed space?

Did you replace the thermocouple 7 years ago AND recently or just 7 years ago? If you only changed the thermocouple 7 years ago then replace the old thermocouple with a new one and you should be all set.

If you have recently changed the thermocouple then you could possibly have gotten a defective thermocouple (I've had a few over the years) or the thermocouple may not have seated properly or been tightened enough. Here, install a new thermocouple and see if that fixes all.

Otherwise, the gas valve itself could be defective... shutting off even though it receives the proper signal from the thermocouple. Here, you would contact the sears technical department so they can tell you how to test the gas valve for continuity, etc. and see if they can resolve this for you. If the gas valve is defective I would recommend replacing the entire water heater as it is nearing its last leg at 13 years old (average life span is between 10-15 years).

First, try the thermocouple change out (again?). Let us know what happens, OK?

Mark