I am sure this has been asked before, but I am going to ask it again. The pilot light on my hot water heater will not stay lit. For the last few days I could relight it and the burner would go out after about 10 to 15 min. After reading some stuff on this and other sites, I decided to replace the thermocoupling. After replacing that, on the first relight it did the samething as I mentioned above. Now the pilot light will only stay lit if I have the thermostat set to the vacation setting. As soon as I try to turn it up to the warm or hot setting the pilot light goes out. Is there anything else I can try on my own to correct the problem, because I really do not have the money to call a repair man and I am getting tired of taking cold showers. Lol:eek: Thank you for any help and advice.

Ok, it is noe the next day and the pilot light will light and the burner will kick on, but it will only stay lit for about 5 to 7 min, then the burner and pilot light just go out. Does anyone know what could be causing this problem? Or could you point me to a previous post oabout the same problem. Thanks for any help.

Pfunk:

How old is your water heater? I'm betting it's pretty new. Let me know for sure OK.

I'm thinking you may have a vapor switch that is causing issues.

MARK

Quote:

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Originally Posted by massplumber2008

Pfunk:

How old is your water heater? I'm betting it's pretty new. Let me know for sure OK.

I'm thinking you may have a vapor switch that is causing issues.

MARK

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I am not exactly sure how old the water heater is. It was in the house when we moved in and I did not think to ask the previous owner hoe old it was. It has a signature and date on it, like the previous owner had it inspected or maybe it is the date it was installed. The year is 1999, so the water heater is at least 10 years old.

If you can... get me the name of the heater, the model number and the serial number.. ok? These are usually found on the front middle of the heater on a sticker with lots of numbers.

Get me that info. And tomorrow I can tell you if this is something you can fix or not. I will need to talk to the manufacturer to know for sure... ;)

Let me know...

MARK

Sorry it took me so long to get the info for you, but I had to help the wife with something. Anyway, here is the info:

Name: A.O. Smith
Model #: FSG 40 242
Serial #: ME99-0058162-242

Thank you for helping me out with this.

Would changing the thermostst do anything?

Hi Pfunk...

OK... water heater is out of warranty since 2005. This water heater is not the newer kind of heater so there is no vapor switch.

My guess is that you may have either over-tightened or under-tightened the thermocouple nut at the gas valve.

Here, remove the nut where the thermocouple joins the gas valve and pull the thermocouple out. Then reposition and set back into place... should insert about a 1/2" before it bottoms out. Now re-tighten the nut hand-tight plus a 1/4 turn and then try to re-light the pilot and see what happens.

If that fails then I would have you install a completely new thermocouple... could be as simple as having a defective thermocouple... rare, but it does happen.

Finally, if that fails then it is probably a bad gas valve... but with heater being 10 years old it would probably be best to install a whole new heater as gas valve replacement can be expensive if you hire a plumber.

Before exploring that try the recommendations above and let me know what happens... ok?

MARK

I tried the untighten the thermocouple screw and repositioned it and then relit it. It lasted 15 min then went out. I might try a new one, but I just replaced it 3 days ago. I have to take my 4 yr old somewhere now so that is all I can try right now. I forgot to say that my dad and I replaced the thermostat about 3 or 4 years ago. I am really considering just getting a new one. Once again, thank you for your help.

Hi Pfunk,

Let me share this with you a few months ago a friend of mine had the same problem, he had replaced the thermocouple and still the pilot would not stay let, I asked him to take the thermocouple back to home depot because it was only 3 days old and get a replacement he did and it worked, good luck.

John