Gas fireplace thermocouple question

[Richard]

Last year, I finally remembered to ask about my fireplace. I remove my propane tanks (propane ventless) every year and the gas leaks out of the lines. Every fall when I reinstall them, it takes maybe 30 minutes of attempts to get the pilot light, lit.

I was told that I simply needed to put heat to the thermocouple and it will let the gas flow more freely.

I'm preparing to finally hook up my tanks this year and remembered this question/answer HOWEVER....

What I don't know is... do I use a match? How about my propane/solder kit? Perhaps my MAP gas solder torch?

How much heat do I need?

I've seen a picture of a thermocoupler on the internet. Looks like a 'pencil' (for lack of better word) with some wires coming to it?

Anyone have a picture of a thermocouple in a gas fireplace or will it be obvious when I take the logs out? (I didn't take them out last night as the wife had just vacumed there and I know as soon as I touch them I'll probably get dirt on the floor and get smacked upside the head :confused2

 

[Travelover]

I used to shut off my gas furnace for the summer and had this problem. I used a propane torch to heat the thermocouple. You just need to get the thermocouple hot, you don't need to try to melt it. You'll know if it is hot enough if the gas continues to flow after you release the button. Use Google images to search for "thermocouple".

 

[Richard]

Ok, so implicit in that is I could probably use the 12" butane lighter that I have to start the charcole grill with?!

:thumbsup:

 

[Travelover]

Ok, so implicit in that is I could probably use the 12" butane lighter that I have to start the charcole grill with?!

:thumbsup:

Yes. It just needs to burn long enough to bleed the air from the line. A really long fireplace match might work.

 

[tommu56]

Yes the 12" lighter will work the flame only has to be same as the pilot just don't let it go out you will see air blowing lighter flame around out the pilot orifice
If you want to speed it up when TC is hot and keeping the lighter flame on the TC and pilot assy turn on the burner on it will light off the lighter purging the air out faster just be careful when doing this burner might pop and go off and on or burn slow till it gets air all out of line.

Can't you put a ball valve just after tank and turn it off before moving tank at the end of season keeping line full of propane?
Then only the pig tail will have air in it and it shouldn't matter much.

tom

 

[ragkar]

A thermocouple consists of two different metals (I don't remember their names) tack welded together. That weld is where the voltage is generated and you don't want to melt it, but I assume that a lpg flame is too cold to do that.
The weld should be placed at the intersection of the flame inner cone (light blue) and the outer cone.
I had troubles last year keeping it working. The fix was to buy a couple feet on quarter inch clear plastic tubing at the auto supply and blow (breath) out the crud on the pilot light nozzle.
Use a spray bottle of detergent like simple green to find that leak.

 

[johnk]

You are better off cracking open a union or a drip leg on the unit and purging out the air there. If you don't know what you're doing you will look pretty silly with singed eybrows and a hairless arm. If you are a pro you can heat the thermocuple in the pilot postion for 7 seconds with a match or what ever and turn the control valve to the ON position with the match or torch directed at the runner tube on the burner till she ignites. If you you don't know what you're doing don't try it or you will be in the Emergency room. Just my 2 Cents. I work for a gas utility..

 

[kenmac]

That's called cheating the pilot safety & if you aren't experenced in doing this. Then don't. If you aren't careful, things can & will go wrong real quick

 

[ragkar]

It sounds like your logs don't have a spark lighter and everyone is warning you of the dangers of using a match or a cigarette butane lighter. You can buy a spark lighter from places that sell recreational vehicle supplies. It looks like one of those charcoal grill lighters and costs about $5. Amazon probably has them also.

I just happened to think that an oxy-acetylene welding torch sparker-lighter would probably work. And they are cheaper and more commonly found.

 

[Richard]

You are better off cracking open a union or a drip leg on the unit and purging out the air there. If you don't know what you're doing you will look pretty silly with singed eybrows and a hairless arm. If you are a pro you can heat the thermocuple in the pilot postion for 7 seconds with a match or what ever and turn the control valve to the ON position with the match or torch directed at the runner tube on the burner till she ignites. If you you don't know what you're doing don't try it or you will be in the Emergency room. Just my 2 Cents. I work for a gas utility..

That's called cheating the pilot safety & if you aren't experenced in doing this. Then don't. If you aren't careful, things can & will go wrong real quick

It sounds like your logs don't have a spark lighter and everyone is warning you of the dangers of using a match or a cigarette butane lighter. You can buy a spark lighter from places that sell recreational vehicle supplies. It looks like one of those charcoal grill lighters and costs about $5. Amazon probably has them also.

I just happened to think that an oxy-acetylene welding torch sparker-lighter would probably work. And they are cheaper and more commonly found.

I don't know what a spark lighter is unless it's the little push button "clicker" that puts a spark out next to the pilot. If that's it then I DO have a spark lighter (that works).

I hooked everything up the other day, went through my "click click click click" process as I tried to purge my pilot line. I then got the 12" lighter BUT, had no clue where to heat.

(I do not know what the thermocouple exactly looks like) so I warmed the base of where the pilot flame would exit.

Not feeling too comfortable about this, I had the vision of me flying through the air as my house is wasted by a LP explosion. This was not a comforting thought so I figured I'd simply do it the old fashoioned way....click bleed...click....bleed...click...bleed.... and it finally kicked off.

Simply seemed to me that there were too many reasons to NOT put an open flame next to propane carrying lines and no reasons other than an attempt to save 10 minutes (maybe 20) of annoyance, to do it.

I figured I'd rather waste the time safely than save it dangerously.