Flue fire with unusual Fisher certified stove

[davester]

Howdy - first post here.I bought this certified Fisher "The Flame " model last fall on CL. Never knew that Fisher made any certified stoves - this one was made in 1985 by N3 Distributing in Eugene, Oregon. It was about the right size for my home and, having used a Fisher stove for years, I knew they were well built.I installed a couple of water heating boxes in it, each measuring 1 1/2" x 6" x 18" and thermosiphoning together into a 40 gallon water heater.I get tons of hot water which is good, because in the winter, the wood stove is my only source of hot water.The water heating boxes are mounted where the firebricks were on either side of the firebox.
The stove has a sliding plate to close off the flue when recirculating flue gasses for more complete combustion.Above this sliding plate is a round baffle plate with several holes in it, about 1/2" in diameter.
I could tell that the flue pipe , which is about 18 ft. of straight pipe, was building up a fair amount of creosote ever since I began using the stove.Burning dry Madrone and Fir. I figured that this was probably due to the amount of surface area of the water heating boxes creating some condensation ? Periodically I would hear chunks fall down the flue pipe.I tend to close the stove down at night and then open it up in the morning to get the fire going. A few days ago, I banged on the stovepipe a coupe of times and a lot of creosote fell down and began to ignite on top the the flue baffle plate. There is no way for the loose creosote to fall back into the firebox.In no time, the stovepipe was red hot even with the stove closed down.
I am wondering about the idea of removing the baffle plate so that any loose creosote can fall back into the firebox rather than building up on the baffle plate.Any reason not to ? This would make it way easier to clean the flue as well rather than having to remove the pipe from the stove and vacuum it up and all that.
Any thoughts - thanks -Dave

 

[coaly]

I'll move your post to the Fisher Forum;
You're extracting too much heat (if the chimney is proper type) or not keeping the flue temperature above 250* to the top.
NEVER use any Fisher Stove without firebrick.
You mention "Flue Pipe"?? There is Chimney Flue, (Insulated stainless steel Class A Chimney) and connector pipe that connects the stove to chimney. You should have a thermometer on the single wall pipe before exiting into chimney to run at the correct temperature.
Do not remove the baffle plate. We need to make sure you have chimney pipe and not single wall all the way up first.Insulated chimney pipe should not cool that much to form that much creosote. Something is way off.

Search TF-88 in the Fisher Forum to find out how rare your stove actually is. It is one of 4 known to exist. Only 50 were made on the East Coast, your manufacturer was the only one on the West Coast. I have no numbers of those made there.

 

[bholler]

Insulated chimney pipe should not cool that much to form that much creosote. Something is way off.

he replaced the firebrick with water heat exchanger boxes which are stealing to much heat from the firebox. It will never work right like that And now he has big holes drilled in the side of this rare stove.
I don't get the fascination you guys have with the common fishers honestly but the more uncommon stuff can be pretty cool and this is about as uncommon as it gets for fishers.

 

[davester]

Thanks Coaly - to make it more clear I have about 9 ft. of single wall stovepipe coming off of the stove and then about 9 ft. of insulated pipe beyond that. One piece of info that I didn't mention in the first post - the guy who sold it to me said that a previous owner had welded some el metal just below the sliding flue plate to hold a firebrick because he was freaked out by the single wall pipe getting red hot. ( that firebrick is not in place and the el metal ) Good idea about getting a thermometer on the single wall - I'll do that. I looked at some of the archived discussion about the TF-88. Does there exist on the forums a manual for it ? What would be the problem with removing the baffle plate ? - Dave

 

[bholler]

What would be the problem with removing the baffle plate ?

It would negate any efficiency they were able to get out of the stove at that point you might as well be burning an old inefficient one like any of the original fishers. I don't know how efficient these stoves are but I am sure they are much more efficient than the original ones. That was until you put all that water in the box now not so much

 

[davester]

What about replacing the steel baffle plate with a removable masonry plate like a lot of newer stoves have ? That way, when I clean the flue pipe, the creosote will fall into the firebox and make it easier to clean up.

 

[bholler]

What about replacing the steel baffle plate with a removable masonry plate like a lot of newer stoves have ?

Isnt the steel baffle removable? If not why not just make it removable like you would with a ceramic one?

 

[davester]

The baffle plate is above the sliding flue plate.It looks like it would be hard to get at it w/o taking the single wall pipe off of the stove, which I was hoping to avoid each time the stovepipe gets cleaned -

 

[bholler]

The baffle plate is above the sliding flue plate.It looks like it would be hard to get at it w/o taking the single wall pipe off of the stove, which I was hoping to avoid each time the stovepipe gets cleaned -

Well if you were to replace it with something else it would have to be in the same position in order to make it work the same so I dont see what it would gain you. Just get a telescoping section of pipe and it wont be a big deal to pull the pipe.

 

[davester]

Probably right.I actually do have the telescoping pipe so tomorrow I'm giving it a try and see how it goes.Think I just need to run some hotter fires more often to keep the creosote from building up so much - thanks

 

[bholler]

Think I just need to run some hotter fires more often to keep the creosote from building up so much - thanks

No you need to get a pipe thermometer and run at proper temps all the time. The idea of running hot every so often does not work you need to burn correctly all the time. Which honestly may not be possible with all of the heat you are loosing to the water

 

[CamFan]

No you need to get a pipe thermometer and run at proper temps all the time. The idea of running hot every so often does not work you need to burn correctly all the time. Which honestly may not be possible with all of the heat you are loosing to the water

That is a TF-88. We called that the toilet seat door. There was another door with double lines. The plate inside acting as a baffle is stainless. It could be made for a mobile home for outside air or free standing. We also made 50 inserts. I know where several are. I have drawings, test reports, and some wear parts. Ken ??? Designed it and it passed the first phase of Epa testing.


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[davester]

Thanks for the info.The door never bothered me. - Dave