# Thernal Coupler change - Gas Fireplace



## HauteShots (Dec 16, 2010)

The other night I noticed the pilot light on one of my gas fireplaces was out. I followed the instructions to restart it but not only would the igniter not light the pilot but even if I lit it with an open flame, it would not stay lit. I tried cleaning it with a wire brush and such but no good. At this point I am assuming it's the thermal coupler that is bad. I read how easy it was to change these but when I went to remove it, closer inspection seems to reveal that the coupler is riveted to the pilot assembly. 

Does this mean I need to replace the entire assembly or did I miss something?







Thank you!


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## paul52446m (Dec 16, 2010)

HauteShots said:


> The other night I noticed the pilot light on one of my gas fireplaces was out. I followed the instructions to restart it but not only would the igniter not light the pilot but even if I lit it with an open flame, it would not stay lit. I tried cleaning it with a wire brush and such but no good. At this point I am assuming it's the thermal coupler that is bad. I read how easy it was to change these but when I went to remove it, closer inspection seems to reveal that the coupler is riveted to the pilot assembly.
> 
> Does this mean I need to replace the entire assembly or did I miss something?
> 
> ...


 You are calling the coupler the 1/2 inch round part on the far right side of your pic.?  Was the sparker sparking When you tried to lite it? 
 Where the pilot line ties to the pilot assembly, if you take the pilot line off there is a orifice in there that has a very small hole in it that might have to be cleaned out. When the flame is lite you should have a blue flame that comes out around the thermocouple about 1/2". Does you coupler have wires coming
 from it, if so it is called a power pile. That sparker need to be cleaned with emery cloth or sand paper. Later Paul


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## HauteShots (Dec 17, 2010)

paul52446m said:


> You are calling the coupler the 1/2 inch round part on the far right side of your pic.?  Was the sparker sparking When you tried to lite it?
> Where the pilot line ties to the pilot assembly, if you take the pilot line off there is a orifice in there that has a very small hole in it that might have to be cleaned out. When the flame is lite you should have a blue flame that comes out around the thermocouple about 1/2". Does you coupler have wires coming
> from it, if so it is called a power pile. That sparker need to be cleaned with emery cloth or sand paper. Later Paul


Hi Paul,

Yes, going by this diagram I saw 
	

	
	
		
		

		
		
	


	




 I assumed he thermal coupler was the white tube with the metal "probe" sticking out of it. 

Yes, I can see a small blue spark when I push the ignite button but the pilot doesn't light. If I use a cigarette lighter the pilot will light but will not stay on, even after 1 or 2 minutes of holding the pilot adjuster knob in. 

I also found this diagram below which is not exactly what my pilot looks like but I now get an idea of where the cleaning hole is ...  Is this what you are talking about:






I will take the assembly off tonight and clean it and update to whether that fixed the problem or not.

Thank you!


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## paul52446m (Dec 17, 2010)

HauteShots said:


> Hi Paul,
> 
> Yes, going by this diagram I saw
> 
> ...


  Yes there is a small orifice and the hole is very small. There may be a air way going in around this orifice. that also gets plugged up. That power pile need a good sharp blue flame going around it. Check all wires to make sure they are clean and tight. If your pilot is burning right and it won't stay lite than it would be ether a bad power pile, bad set of contacts or the magnet in the gas valve is too weak. 
 Later Paul


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## HauteShots (Dec 18, 2010)

Ok so i disconnected the gas line to the pilot and I have this updated photo below. According to some install instructions it looks like I have a thermopile not a thermo coupler. I checked over and over again and there is no small hole to be cleaned anywhere that I can see. I used some sandpaper to clean the pilot hood and thermopile but the pilot doesn't seem to stay lit although the ignitor is working again. 

I guess I need to change the thermopile?


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## paul52446m (Dec 18, 2010)

You never did tell me if you have a good blue pilot flame that goes around the power pile
 about 1/2" down from the top and around the power pile. If you do then your pilot doesn't need cleaning. If you have a lazy yellow flame then it will not heat up the power pile enough to make any power. 
 When you took off the pilot gas line, the orifice with the small hole is up inside the pilot where you took off the pilot line. But those orifices are hard to get out and if you have a good pilot flame then your ok. 
 You would have to have the power pile power tested to see if it needs replacing.
 At your gas valve , take off your thermostat wires but leave the power pile wires on then lite the pilot and see if it stays on. If you can't electrical test the power pile  then i guess you could just replace it. You would have to test millivolts to test it.  Later Paul


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## HauteShots (Dec 20, 2010)

Hi Paul,

Yes, the flame is big an blue. I don't have an ohms meeter so I cant test the thermopile. I looked on the 'net for the manufacturer of my fireplace (Superior) and they only have one safety type doc with that model number on it and nothing else. Can I just purchase and after market one if I make sure its the same length and millivolts?

Thanks again for all your help!


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## paul52446m (Dec 20, 2010)

HauteShots said:


> Hi Paul,
> 
> Yes, the flame is big an blue. I don't have an ohms meeter so I cant test the thermopile. I looked on the 'net for the manufacturer of my fireplace (Superior) and they only have one safety type doc with that model number on it and nothing else. Can I just purchase and after market one if I make sure its the same length and millivolts?
> 
> Thanks again for all your help!


    Yes you can just buy a power pile at any heating whole sale house. The length is not important but the millivolt power is. It has been my experience that the cheep one don't work as good, so i have always bought Honeywell. They may cost more but the work better, and give you more power. Later Paul


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## HauteShots (Dec 30, 2010)

Hi Paul,

I went and picked up a new Honey Well thermopile for $56. It is the same size and milivolts as the one I replaced. I put it in and lit the pilot manually and held the button for about two minutes and the pilot still doesnt stay lit. There are two wires going to the thermosat and i disconnected both of them but still left power pile leads on and the pilot still doesnt stay lit either. Below is a photo of what it looks like... 






Do you have any idea of what I should try next?


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## HauteShots (Dec 31, 2010)

Hi Paul,

I also took this video of the pilot flame:


Pilot Flame Video


 Does the flame look good?


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## paul52446m (Dec 31, 2010)

HauteShots said:


> Hi Paul,
> 
> I also took this video of the pilot flame:
> 
> ...



I did not see your video, I don't know what program i would to find to open it.
 If i was at your home checking this system out. First i would lit the pilot and see if is was blue and surrounding the power pile about 1/2" down from the top of the power pile and about 1/2" around the power pile. If it wasn't doing this then i would clean the pilot. 
 After the pilot is cleaned properly then i would take off the two power pile 
 wires from the gas valve, take my tester,lite pilot a  and test the power pile to see if it is good or needs replacing. If the power pile tests ok and i put the wires back on the gas valve and the pilot still won't keep going, then the problem is in the magnet in the gas valve. later paul


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## HauteShots (Jan 2, 2011)

Hi Paul,

The video should be able to open with quick time or windows media player. None the less I went through all the steps above and I am concluding that the problem is magnet. Do I have to replace the whole valve or can I just replace the magnet? Where is the magnet in the valve anyway?

Thank you for all your help.


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## HauteShots (Jan 9, 2011)

paul52446m said:


> I did not see your video, I don't know what program i would to find to open it.
> If i was at your home checking this system out. First i would lit the pilot and see if is was blue and surrounding the power pile about 1/2" down from the top of the power pile and about 1/2" around the power pile. If it wasn't doing this then i would clean the pilot.
> After the pilot is cleaned properly then i would take off the two power pile
> wires from the gas valve, take my tester,lite pilot a  and test the power pile to see if it is good or needs replacing. If the power pile tests ok and i put the wires back on the gas valve and the pilot still won't keep going, then the problem is in the magnet in the gas valve. later paul


Hi Paul,

I was wondering if you could offer some more insight on the magnet in the gas valve. Is this something that can be replaced or do I have to replace the entire valve?

Thank you.


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## HauteShots (Mar 23, 2011)

Ugghh FirePlaceGuys dot com quoted $229 plus shipping for a new gas valve! That sounds a bit excessive to me. Has anyone replaced one of these valves before and know if that quote is way out of line?


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## paul52446m (Mar 23, 2011)

HauteShots said:


> Ugghh FirePlaceGuys dot com quoted $229 plus shipping for a new gas valve! That sounds a bit excessive to me. Has anyone replaced one of these valves before and know if that quote is way out of line?



I have not bought on off those small valves in years. I wouldn't be surprised 
 at $175.00 or more. All you can do is check around.   Paul


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## donmorgan (Mar 29, 2011)

I just had the same problem,  it was the ODS,Oxygen Depletion Sensor, it will give you the same symptoms as a bad thermocouple. Cleaning them especially with compressed air over 30lbs pressure or abrasion will render them useless. I would get the whole assembly. That's what I did and my heater is working like new. I found one one EBAY for half of what the authorized service center wanted.


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## HauteShots (Mar 29, 2011)

What does the ODS look like?


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## donmorgan (Mar 30, 2011)

The ODS is an integral part of the pilot light assembly and is located where the gas line attaches, it is a small diaphragm that in the diagram on your post is between the clean out hole and the gas line connection. It is built in and cannot be replaced separately. Replace the entire pilot assembly module, That is going to be the best fix.  
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