Outdoor Wood Furnace Info

All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: big cat on November 10, 2014, 08:30:02 PM

Title: Stack Flames
Post by: big cat on November 10, 2014, 08:30:02 PM
Often at times I have flames shooting out of my stack. I have a NCB175 and I extended the stack with 3' of steel pipe. Is this normal/bad? I assume there is heat loss as a result, how do I trap the heat? Thanks.
Title: Re: Stack Flames
Post by: walkerdogman85 on November 10, 2014, 10:16:27 PM
My hardy h-4 does it once in a while too. I usually load it up with cardboard and leave the doors open to get the fire roaring which "cleans it out" as suggested by a forum member. I'm not sure how you would capture the heat loss?
Title: Re: Stack Flames
Post by: DaveWertz on November 11, 2014, 12:02:24 AM
Its normal nothing to worry about. Sometimes when Im loading the stove and the fire gets going pretty good it looks like a blow torch coming from my stack. I just let it go for a few minutes, it cleans it out pretty good then I just take a old garden hoe and scrap the sides of the firebox.
Title: Re: Stack Flames
Post by: RSI on November 11, 2014, 09:09:39 PM
How old is the NCB175?
Title: Re: Stack Flames
Post by: LittleJohn on November 12, 2014, 07:07:23 AM
BREAK OUT THE MARSHMELLOWS  :thumbup: Just kidding, toasting marshmellow from the top of ladder is not recommended

Sorry, back to the real issue, do the flames ALWAYS shoot out the stack or is it at specific times (like during loading or at the end of a call for heat, etc.).  Cause if it only happens during isolated cases, like loading the firebox, I think the flames should be OK??  But if it isn't occasional, it might be a sign of something else, not sure what that something else is but somewhere here might have a better idea.

Title: Re: Stack Flames
Post by: walkerdogman85 on November 12, 2014, 03:58:12 PM
Mine does it when I load with cardboard (intentional) clean out.. Very seldom during normal operation. Once I did see it when the stack was dirty
Title: Re: Stack Flames
Post by: AirForcePOL on November 13, 2014, 03:23:18 PM
I used to get flames out of the stack on my Hardy all the time.  Usually when I had a good fire going and right after I stirred the hot coals up durring a burn.  It never caused any issues.  I did notice that when it was burning that hot, I would get some hot ashes coming out of the stack every once in a while.  I would just make sure you keep the area around your stove free from leaves or anything else that could easily ignite. 
Title: Re: Stack Flames
Post by: userdk on November 13, 2014, 04:05:25 PM
Happens pretty often. Especially with single pass or no smoke pass furnaces.
Title: Re: Stack Flames
Post by: yotehunter66 on November 13, 2014, 05:52:58 PM
Same here. Looks cool when it does it a night.
Title: Re: Stack Flames
Post by: walkerdogman85 on November 13, 2014, 05:56:47 PM
I haven't ever had any issues with it either.. I just added 4 foot to my stack and still have some hot ash coming out.. I live right on the edge of woods with a lot of leaves around and haven't seen anything happen yet.
Title: Re: Stack Flames
Post by: big cat on November 13, 2014, 08:04:22 PM
Very similar to AirforcePOL it happens somewhat often, usually after stirring coals and adding wood while blower is engaged. I cover my wood with tarps that look like swiss cheese due to the ashes coming out of the stack.
My NCB175 is ~5 years old.
Title: Re: Stack Flames
Post by: AirForcePOL on November 13, 2014, 08:25:07 PM
I noticed some flames coming out of the stack on my 5000e tonight.  I had one hell of a fire goin in it. 
Title: Re: Stack Flames
Post by: RSI on November 13, 2014, 09:37:33 PM
Very similar to AirforcePOL it happens somewhat often, usually after stirring coals and adding wood while blower is engaged. I cover my wood with tarps that look like swiss cheese due to the ashes coming out of the stack.
My NCB175 is ~5 years old.

Have you tried cutting back the air flow? It sounds like it is getting too much.
How far back does the grate go? If the stove was made before 2009 it may help to cover the back part of the grate. They changed the design in 09 so it wouldn't blow air up the stack.
Title: Re: Stack Flames
Post by: big cat on November 15, 2014, 08:53:03 PM
I never paid attention to how for back the grate goes. I'll have to pull back my coal bed and take a look. I believe my boiler was made before 2009 because I have the older single sheet of metal roof. The boiler came with the house so I didn't buy it initially. would a steel plate work to cover it?
Title: Re: Stack Flames
Post by: RSI on November 15, 2014, 10:39:26 PM
If it was made before 2009 it will have a straight chimney pipe inside the firebox, (they added water jacket around it in 2009) and the air shutoff flap on the fan will have a hinge and a turn buckle for adjusting airflow.

If it was made after 2009 it will have a restrictor plate after the fan.

Unless you have already made adjustments to the air adjustments and it is in the best place, I would try giving it less air.
Title: Re: Stack Flames
Post by: CountryBoyJohn on November 16, 2014, 07:12:01 PM
I noticed some flames coming out of the stack on my 5000e tonight.  I had one hell of a fire goin in it.

Are you sure it want a chimney fire? I've never had flames come out of mine except when I did have a chimney fire. That's write a feat to make it thru 3 bypasses.
Title: Re: Stack Flames
Post by: big cat on November 16, 2014, 07:26:34 PM
Wasn't a stack fire, I think RSI hit it on the head. Its definitely being forced by air out of the stack. My unit has the straight fire box stack and hinge/turnbuckle/flapper blower. I'll get a piece of steel plate to restrict the airflow, since my flapper is already set at a 1/2 inch or so. I would think this should save on wood too, no?
Title: Re: Stack Flames
Post by: RSI on November 16, 2014, 08:51:04 PM
It should use less wood when not doing it.

I would start by covering the back part of the grate. You may need to slightly change the way you load it afterwards so the coals are over the remaining grate. You should be able to lower the flap more. It doesn't take much of an opening on the inlet side of the fan to give it a lot of air.

They used the same fan on models up to the 325 which was about twice the size, so it is easy to give the 175 way too much air.
Title: Re: Stack Flames
Post by: AirForcePOL on November 16, 2014, 08:56:31 PM
I noticed some flames coming out of the stack on my 5000e tonight.  I had one hell of a fire goin in it.

Are you sure it want a chimney fire? I've never had flames come out of mine except when I did have a chimney fire. That's write a feat to make it thru 3 bypasses.

It is possible but I don't think it was a chimney fire.  I could barely see the flames but they were coming out about 6 inches or so.  I had the firebox pretty full and some good flames coming from the font of the stove. 
Title: Re: Stack Flames
Post by: LittleJohn on November 17, 2014, 06:47:49 AM
NOTE!!!

I had flames shoot out of my stack this weekend  :bag:
Apparently you should not try to load wood into OWB, immediately following a burn cycle. :bash: extra oxygen from door being open, did not help things