Old Fisher Grandpa meets new guy to wood burning stoves

[georgiamatt]

Hello all. Great site!
I'm brand new to wood burning stoves and I was just given an old Fisher Grandpa (8" rear exhaust) that I would like to install in my 1,300 sq./ft. bungalow. It's a lot of stove for a small house, but a good friend gave it to me and after placing it on my hearth I love it. I'm having some difficulty in deciding how to run my stove pipe to my existing chimney flue.
My house was built in 1948 and at some point my fireplace was covered up, but not filled in, with rock and mortar and a hearth was built. The back wall had rock and mortar also up to the ceiling and 70" wide. A gas log decorative chimenea looking thing was installed on the hearth with a 7" stove pipe exhausting out of the top of the stove then through the rock and mortar wall/brick and mortar chimney dumping in my 6.5" X 11" terracotta chimney flue. I never was a big fan of this gas burner because it never really provided any heat and took up a large portion of my living room. Then the Fisher came along... It looks great and maybe with some of your guys help I can heat my house this winter.
A few concerns I have are adequate flue size (6.5"X11"), difficulty cleaning out the old fireplace collecting creosote, and the stove exhausting out of the back requiring 3 90* bends preventing a good draft.
I shined a light down the chimney from the roof and from my untrained beginner eye it looked like it was in decent shape with not much creosote build-up and the terra-cotta in place. It is 65 years old, so to address the age of my chimney and the fireplace void behind the wall I was thinking of installing a liner, but I would need a rectangle liner right? This would be over $1000 from Rockford Chimney for a 14' long 6"X10.56" liner kit. That is a little high for my budget. If I were to come out of the back of the stove with a 90* bend, then vertical 44", another 90*, then into the existing hole (opened up from 7" to 8") 12" to the chimney flue will this draft? Should I be concerned with creosote build up in the old fireplace below where the new 8" pipe is tied to the chimney flue? I will be using double wall stove pipe since the top 90* will be 12" from the ceiling. The rest of the pipe will have plenty of clearance with the rock and mortar wall and hearth.
Thank you in advance for any advice you wood stove wizards out there can give.
Matt

 

[Dell]

Matt - Welcome to the forum! Coaly is the resident expert on the Fishers and will likely provide you the wisdom you need when he gets a chance. In the meantime, I will try to respond to some of your questions as best I can. A Grandpa very likely will be too much stove for 1300 SF, especially in Hotlanta, Georgia. I am heating 2500 SF - basement plus two floors with a Papa Bear located in the basement. A baby or Mama bear would likely be a better size fit for your home, but I understand and appreciate that free is free, and you have a good friend indeed to give you a Fisher.

I believe the manual for the grandpa on this site but I can't locate it. That will list install directions and clearances. Your liner should match your outlet, so ideally you want an 8" round liner but I see that you have a 6.5 x 11 flue. 8" round flue area = 50.24 square inches. You have a 71.5 square inch flue. That will impact your draft and your plan for a liner is a good one. Perhaps a 6 x 10" rectangular liner would work? A damper should be installed in the single wall pipe close to the stove. I am not certain on the void behind your wall or creosote buildup you ask about, I imagine that is the blocked off fireplace?
As for draft concern, my install is similar, with three (3) 90-degree elbows (one at the stove, one about 4 feet above stove, and one in the actual masonry chimney). Chimney height is approx. 25 - 32 feet above stove. But my stove has 6" rear exhaust and my chimney is 8x8 terra cotta on the outside of the house (as opposed to a central chimney) - I have a strong draft. I intend to install a 6" liner and insulation to further enhance draft and reduce creosote buildup. And there will be some creosote buildup with these stoves. The chimney, moisture content of your wood, and how you burn your stove it will determine how much, but I am planning on sweeping my entire chimney twice this year and the bottom single wall pipe up to chimney once per month or about every cord burned. Others with less elbows and better chimneys/liners may experience less creosote. Try to season wood for 1 - 2 years before burning. Keep the entire chimney above 250 degrees to eliminate creosote buildup. Temps will go below that at times, such as when the fire is dying out.

A few thoughts: you may want to get a chimney sweep to inspect your chimney thoroughly, small cracks in the terra cotta and missing mortar are the concerns. May want to consider a stove with a 6" exhaust instead, so you could use a 6" round liner without any modifications to your existing flue and potentially get a less expensive liner. It could reach from the stove up to the cap to eliminate concerns about the void area. 6" is the most common stove flue size, so there are tons of options. Your homeowners insurance should know about the woodstove and may require inspection of install/clearances, depending on your local codes, etc. Not sure if your stove is U.L. listed, etc.

You could sell the Grandpa and score a Mama or Baby for same price (around $400 - 600 typically on Craigslist), each has a 6" flue, or even a newer stove if you go in that direction. If you decide to install the Grandpa, it does sound like your flue size and configuration is the main challenge in my opinion. With that solved, you may be opening all your windows and heating the entire neighborhood because it is so much stove. I'd hate to see you go through all that work to use an 8" stove, when you may downsize if the stove is too big for your home. You should read about a baffle if your stove does not have one inside. Also may want to replace the rear and side firebrick if they are in bad condition/broken. That and some stove paint is all I did to mine to restore it.

I love these old Fisher stoves and my wood burning friends think I am crazy for using an old "smoke dragon". But I also have the warmest house of all of them and a 35-year old tank of a stove that does not break or require any parts. Creosote is my main concern, and it does consume some wood, but I think all stoves do. Keep us posted.

 

[930dreamer]

Welcome to the Hearth, can you post a few pics of the beast?