# soot buildup



## hcawthra (Dec 19, 2009)

I was having troubles keeping my Lopi berkshire gas stove going. It would burn for 15 minutes then go out. I'd relight the pilot light and everything would check out but it would do the same 15m burn. I changed the thermopile and thermocouple still same 15m burn. I decided to check my chimney it is a duralast conversion 4" aluminum flex and it had about 2" buildup of soot. Stove has been used for about 6yrs. Is cleaning the chimney needed on a gas stove? Is something misadjusted on my stove? Thanks


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## jtp10181 (Dec 19, 2009)

Not normally, something must be wrong with the stove if you have that much soot in the vent.


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## DAKSY (Dec 19, 2009)

Has your glass also sooted up?
Is there a soot build-up on your logs?
If so, the indication is that your air shutter is not open far enuff...
But, to be honest with you, I've never seen THAT much of  
sooting on a vent system...
How long since the appliance has been serviced?


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## hcawthra (Dec 19, 2009)

The stove has been used about 6-8 yrs, no problem. The glass would get a small amount of soot on it in a season, but very little. I would take the glass out and clean it every spring. There was a small amount of soot on the logs. The air shutter is set to the setting that the manual showed. I did check and its set on the most restricted setting, ie smallest opening.


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## DAKSY (Dec 19, 2009)

hcawthra said:
			
		

> The stove has been used about 6-8 yrs, no problem. The glass would get a small amount of soot on it in a season, but very little. I would take the glass out and clean it every spring. There was a small amount of soot on the logs. The air shutter is set to the setting that the manual showed. I did check and its set on the most restricted setting, ie smallest opening.



ANY amount of soot indicates an air fuel mixture problem.
Is your unit LP or NG?
The air shutter on an LP unit should be WIDE open.
An NG unit should have the air shutter closed somewhat, but never less
than 1/8", AFAIK.


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## hcawthra (Dec 20, 2009)

The Lopi ng stove is working now after I cleaned the soot out of the chimney. The restrictor is in the position called for in the manual. My chimney is 12.5' long. The other adjustment is the air shutter control which  is almost closed, just barely opened. According to the manual "Correct flames should be blue at the base,yellow-orange on the top"  The flames don't ghost or lift and they burn right off the burner holes. A friend that used to be a air/heating man told me that there should be no soot in chimney and maybe if any a slight film on the chimney cap. I watch the flames and see no soot coming off it. Thanks


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## North of 60 (Dec 20, 2009)

I am wondering if the LP conversion kit was ever installed.  Any tags or labels on the gas valve?  Something still fishy.


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## jtp10181 (Dec 21, 2009)

He said he is running NG. I would open the air shutter a little bit.
Was there ever anything else vented into this chimney?


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## North of 60 (Dec 21, 2009)

jtp10181 said:
			
		

> He said he is running NG. I would open the air shutter a little bit.
> Was there any thing every vented into this chimney?



OOOps, thanx. :red:


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## hcawthra (Dec 21, 2009)

There was never anything else connected to chimney. I replaced a wood stove, so I installed a simpson duravent class A chimney conversion kit. 8" id triple wall with the alumium 4" liner. I used the high wind cap. Total length of chimey is 7.5' long. Everything fits and is sealed well.


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## hcawthra (Dec 21, 2009)

I posted that chimney was 7.5' long thats the length of the 4' aluminum inner liner ,the total length  overall is 12.5' long.


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## jtp10181 (Dec 21, 2009)

So its a direct vent stove, correct? You are using a 4" liner through the old 8" wood pipe, which means the fresh air for the stove is coming down the old pipe. Was the class A pipe cleaned thoroughly before installing the gas liner? See where I am going here...


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## DAKSY (Dec 21, 2009)

jtp10181 said:
			
		

> So its a direct vent stove, correct? You are using a 4" liner through the old 8" wood pipe, which means the fresh air for the stove is coming down the old pipe. Was the class A pipe cleaned thoroughly before installing the gas liner? See where I am going here...



I DO! I DO!


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## hcawthra (Dec 21, 2009)

I see where you're going JTP. Yes I cleaned out the 8" pipe myself. I checked the old 8" pipe after I removed the 4" inner liner Sat. and it was clean. I vacuumed out the interior of the stove, again very clean. I have the instructions for the duravent stapled to my stove manual, checked and my install was as recommended. My ac/heater friend told me after I described the symptoms that the stove wasn't drafting. He was correct but I'm wanting to know what caused the build up of soot.


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## jtp10181 (Dec 21, 2009)

I still say to open the air shutter a little. If there is not soot balls hanging off one of the logs the soot must be from fuel/air mixture being wrong.


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## Mr Fixit (Dec 23, 2009)

Ya I agree. Soot doesn't just appear in the venting and no where else. It must be somewhere else in the fireplace. If it hasn't been serviced for 6 years, there is a good chance the aperature is clogged with dust and you will find carbon pillows under the burner tray.


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