Water Heater Question

[Kris.]

I am having, I think, 2 problems with my water heater.

1) the pilot flame is very small and blows out very easily unless there is absolutely no wind (in which case it works fine) From reading I think I need to clean the tubes and the thermocouple up and maybe it will work fine. I am only mentioning this since it may be a clue for my other problem.

2) when the pilot flame blows out and the water becomes cool enough the gas for the burner still comes on. It was my understanding that if there was no pilot light that the gas should not come on to the burner (creating a situation where the gas runs continuously and is not being burned.)

I am wondering if this is normal? It shouldnt be possible for the control to turn on the gas to the burner if the pilot isnt lit , should it?

Any suggestion on how to fix this? I am wondering if i just need to buy a new thermocouple and clean the tube for the pilot light.

Thanks for any help

[AirHeadsRus]

What kind of WH is it? Can you send a pic?
You sure it has a pilot? Mine works on a spark.
Welcome to the group!

[bibbs]

That thing is dangerous! If your not handy,get it fixed. Sounds like the gas valve is not working as it should.Dont know how old it is,I would consider replacing the whole thing.

Bibbs

[Kris.]

Thanks for the replies - let me answer the questions:

It is the original water heater in my 72 Overlander. I cant find the brand name on it.

It definitely does not have electric ignition, and it definitely does have a pilot light.

Here are the pictures - they are big so you may have to be patient:

Here is a link to a picture of the whole unit
http://www.krisdillon.com/photos/camper/IMG_1179.jpg

Here is a lint to a picture of the control valve label http://www.krisdillon.com/photos/camper/IMG_1183.jpg

I am very handy, but I'd like to get some more knowledge going out into the sub-freezing outside to work on it. I am pretty sure that the propane to the main burner should be shut off if the thermocouple is cold, even on a unit this old.

What I dont know is what is causing the propane to not shut off, I am wondering if just replacing the thermocouple will solve the problem or if the problem is some sort of a stuck needle valve inside the control.

[SteveH]

Kris,

From the symtoms you discribe, you have two problems...the pilot orifice is probably restricted, and either the thermocouple is bad, or the burner valve is bad.

You are right in that the gas should not continue with no pilot light. If the heater is original like you say, I believe I would replace the entire thing because even if you fix the gas operation problems, the tank could go at any time.

[Kris.]

SteveH

I agree that the best thing to do would be to replace the entire water heater, but money is tight right now and I have spent about $1k on the trailer in the last few months. I'd like to hold off spending much more for awhile.

Based on what you said I have a question. Once lit the burner does work properly, and once the water is hot enough the burner does shut off properly. In fact if there is no wind at all (and thus the pilot never goes out) the entire unit seems to work fine even on a week long trip. Based on this information would you be inclined to think that the burner valve is ok and that just replacing the thermocouple and cleaning the pilot orfice would solve both problems?

Thank you for your help

[SteveH]

Originally Posted by Kris.

SteveH

Based on what you said I have a question. Once lit the burner does work properly, and once the water is hot enough the burner does shut off properly. In fact if there is no wind at all (and thus the pilot never goes out) the entire unit seems to work fine even on a week long trip. Based on this information would you be inclined to think that the burner valve is ok and that just replacing the thermocouple and cleaning the pilot orfice would solve both problems?

Thank you for your help

In short, yes I think so. I had a heater with the exact same symtoms in our '75, and once I got the pilot orifice clean, it worked good.

The problem is, the orifice is very hard to clean. I made several attempts at it before I got it. The orifice is so small you cannot even see thru it, much less clean it with a drill bit. You have to spray it with a cleaner and then use high pressure air to reverse blow it out. What happens is the aluminum tube going to it get corroded and the white corrosion gets into the orifice. You cannot blow it from the open end as that will simple blow more of the corrosion into the orifice.

At best, it is a trial and error, labor intensive procedure, but can be done because I've done it.

[Crusty]

If you go to a welding supply, you can buy an inexpensive tip cleaner set for a gas welding torch that contains many very small circular files for doing this very thing without enlargening the orifice.

FWIW, I really like my new water heater with the automatic spark igniter and controls to shut off the gas if there is no flame present. I don't worry now about becoming an astronaut in a Do It Yourself space shuttle.

[Inland RV Center, In]

[DO NOT] use any form of any type of pin, wire, or anything resembling those, into any orifice of any LPG appliance.

That is asking for trouble, on a RED CARPET.

There are two very easy ways to clean the orifices, without "ANY" risk of altering the size of the hole.

1. Use a jewelers "Ultra Sonic Cleaner" for about 10 to 15 minutes.

2. Soak the orifice in "LIME-AWAY" for a couple of days or so. Rinse it off, dry it off, and reinstall it.

WOW. How easy.

And, the best part for last............... The only cost might be to treat the wife to something special, , because you used her jewelry cleaner.

Andy

[SteveH]

Again, Andy is right about the orifice being too small to use any type of file or drill. It's also in soft metal and can easily be distroyed.

[Kris.]

Thanks a lot guys, I think I know what I need to do now. I'll try the lime away method, that sounds pretty painless. I am hoping I can get the tubes disconnected from the control without twisting them off, seems like corrosion has fused the tubes to the nuts such that the tubes will twist with the nuts. Maybe some wd-40 will help.

Also, can someone confirm that:
1) the thermocouple should prevent the control from providing gas to the burner, and not just shut off gas to the pilot? i.e. gas going to the burner when the pilot is not lit should never happen, even with a unit this old.

2) a thermocouple can fail in such a way that the control fails to shut off the gas when the pilot is not lit, vs. never letting the gas through to the pilot or burner. i.e. my thermocouple has failed thus the control isnt preventing gas from going to the burner when the pilot has blown out.


thank you guys very much - this site has made getting our airstream on the road again infinitely easier and more enjoyable

[SteveH]

Originally Posted by Kris.

1) the thermocouple should prevent the control from providing gas to the burner, and not just shut off gas to the pilot? i.e. gas going to the burner when the pilot is not lit should never happen, even with a unit this old.

2) a thermocouple can fail in such a way that the control fails to shut off the gas when the pilot is not lit, vs. never letting the gas through to the pilot or burner. i.e. my thermocouple has failed thus the control isnt preventing gas from going to the burner when the pilot has blown out.

Not exactly shure of all the ways that a thermocouple can fail, but in no circumstance should the control allow gas to go to the main burner when the pilot is not lit.

If your "thermocouple has failed thus the control isnt preventing gas from going to the burner when the pilot has blown out", you definately need to replace at least the thermocouple, and possibly also the control.