Fisher Grandpa Bear installation Question

Scorpiorias

New Member
Sep 22, 2019
3
PA
Hi gang, I have a fisher Grandpa Bear rear exit I intend to put to a good use in my home. I am experimenting on the idea of using this stove like an insert type stove.

The plan is to cut a 3 feet wide opening into the hallways wall and building a masonry type fire place that will terminate at the ceiling. It will be constructed with cinder blocks on all sides, a concrete slab floor and exhausted through a double walled stove and chimney pipe. Basically buiding a cider block box around the stove with about a 6 inches clearance on all sides.

My question is about clearances. I assume cinder blocks aren't combustible. The combustible ceiling will have more than adequate space between it and the stove. I assume if the house came with the proverbial outdated masonry fireplace, I could shove in the stove and use it that way without any clearance considerations or code violations. With that said, Why CAN'T I build a masonry fireplace and use my fisher stove like an insert?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
19,050
central pa
Hi gang, I have a fisher Grandpa Bear rear exit I intend to put to a good use in my home. I am experimenting on the idea of using this stove like an insert type stove.

The plan is to cut a 3 feet wide opening into the hallways wall and building a masonry type fire place that will terminate at the ceiling. It will be constructed with cinder blocks on all sides, a concrete slab floor and exhausted through a double walled stove and chimney pipe. Basically buiding a cider block box around the stove with about a 6 inches clearance on all sides.

My question is about clearances. I assume cinder blocks aren't combustible. The combustible ceiling will have more than adequate space between it and the stove. I assume if the house came with the proverbial outdated masonry fireplace, I could shove in the stove and use it that way without any clearance considerations or code violations. With that said, Why CAN'T I build a masonry fireplace and use my fisher stove like an insert?
It would almost need to be a built to code fireplace to do it up to code but honestly it sounds like allot of time effort and money for an old inefficient stove. And it would be made more inefficient by stuffing a radiant stove like a Fisher into a concrete box.
 

Scorpiorias

New Member
Sep 22, 2019
3
PA
It would almost need to be a built to code fireplace to do it up to code but honestly it sounds like allot of time effort and money for an old inefficient stove. And it would be made more inefficient by stuffing a radiant stove like a Fisher into a concrete box.
I appreciate the insightful thoughts. The manual calls for a 39.5 clearance space. That's a lot of acreage dedicated to the stove as I will like it to be located in the hall way for a more efficient distribution of heat. Sheet metal wall protection defeats the aesthetics of having a wood stove..(at least in my view).

I have a 2800 sqf dwelling space. I am guessing this stove is a "stand in the middle of the room" type stove. If I move it into a small study room or basement, it gets tricky heating the entire house. Any ideas?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
19,050
central pa
I appreciate the insightful thoughts. The manual calls for a 39.5 clearance space. That's a lot of acreage dedicated to the stove as I will like it to be located in the hall way for a more efficient distribution of heat. Sheet metal wall protection defeats the aesthetics of having a wood stove..(at least in my view).

I have a 2800 sqf dwelling space. I am guessing this stove is a "stand in the middle of the room" type stove. If I move it into a small study room or basement, it gets tricky heating the entire house. Any ideas?
Save the money that would be spent on this crazy install and buy a new stove with tight clearances that will give you more heat out of each price of wood. Old fishers and similar were great for their day. But the new stuff is just way better in just about every way
 

Todd67

Minister of Fire
Jun 25, 2012
841
Northern NY
Sounds like a challenge regardless of the stove you use.

The Fisher will put out a lot of heat, and it can hold a fire for 10+ hours. I heat my 1600 sq ft 2-story house with a Fisher Mama Bear. But I have a fairly open floorplan downstairs. The mudroom on the opposite end of the house can be 10 degrees colder than the living room where the stove is cornered. The upstairs is also about 10 degrees colder, but that's not bad when you consider how drafty and poorly insulated my house is.

I wouldn't trade my Fisher for a new stove, but that's my opinion based on my needs and expectations of a wood stove. You can add a simple plate steel baffle plate that will increase the efficiency of your Fisher.

Bholler has a lot of knowledge and experience. Expect him to try to talk you out of that Fisher and into a new stove until he is blue in the face ;). He knows that some of us are diehard Fisher stove fanatics and won't budge.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
19,050
central pa
Sounds like a challenge regardless of the stove you use.

The Fisher will put out a lot of heat, and it can hold a fire for 10+ hours. I heat my 1600 sq ft 2-story house with a Fisher Mama Bear. But I have a fairly open floorplan downstairs. The mudroom on the opposite end of the house can be 10 degrees colder than the living room where the stove is cornered. The upstairs is also about 10 degrees colder, but that's not bad when you consider how drafty and poorly insulated my house is.

I wouldn't trade my Fisher for a new stove, but that's my opinion based on my needs and expectations of a wood stove. You can add a simple plate steel baffle plate that will increase the efficiency of your Fisher.

Bholler has a lot of knowledge and experience. Expect him to try to talk you out of that Fisher and into a new stove until he is blue in the face ;). He knows that some of us are diehard Fisher stove fanatics and won't budge.
The difference between me and you though is that I have used lots of stoves including a couple old fishers. And lots of new stuff as well. And yes fishers are pretty good old stoves. But they really don't compare with most of the new stuff. I don't really ever try to talk people out of old stoves. I just turned to make them aware of those stoves short comings
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
19,050
central pa
Infact my favorite stove was a Cawley lemay 600. It as designed at a similar time as the fishers but was advanced so far past those simple steel boxes. It actually had a primitive secondary combustion system.
 
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Todd67

Minister of Fire
Jun 25, 2012
841
Northern NY
@bholler , I hope you know I'm just messing with you. I wouldn't know how to use a new stove if you put one in front of me.

My lack of wood stove experience is because I grew up in small cities, then spent 20 years in the army, which involved moving every 3 years. I learned a lot through research before I started burning wood in 2012, and I'm still learning. But as you know, I wouldn't trade my Fisher for anything out there:)
 
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coaly

Fisher Moderator
Staff member
Dec 22, 2007
3,550
NE PA
I appreciate the insightful thoughts. The manual calls for a 39.5 clearance space. That's a lot of acreage dedicated to the stove as I will like it to be located in the hall way for a more efficient distribution of heat. Sheet metal wall protection defeats the aesthetics of having a wood stove..(at least in my view).

I have a 2800 sqf dwelling space. I am guessing this stove is a "stand in the middle of the room" type stove. If I move it into a small study room or basement, it gets tricky heating the entire house. Any ideas?
Free standing stoves radiate in all directions. A Fisher Fireplace Insert radiates from the front half that protrudes from the hearth, and the back has an air chamber around it which uses convection heat, which is heated air blown into the room with a blower. This extracts the heat from the Insert instead of being absorbed into the masonry. It was thought by using the mass of a fireplace, the heat would radiate into the building. The problem is that it also radiates out the back, and up through the roof, defeating the purpose of heating the mass.

The reason you don't want to enclose a freestanding stove, is due to warping the side and rear sheets due to uneven heating.
As the stove radiates heat off of it, this keeps the surface temperatures equal all the way around. When placed in a fireplace or alcove, heat radiates off the front more than the sides or back. When the enclosed rear stays hot, and the front cools, it creates problems. This uneven heating was the cause of warped sheets, cracked welds, and one of the few reasons for any warranty problems.

Cement blocks do not take well to extreme heat. They break, crack, and break down if not protected by a firebrick covering or liner. Basement walls are prone to cracking behind these stoves as well during extreme cold outside.

You must have a Series III Grandpa? (it will have a UL label on the back) to quote 39 1/2 inch clearances. That is to the rear, 42 inches side.
For reduced clearance to combustibles you can build a UL approved heat shield with cement board and face with tile, brick or stone. Reduced clearance is then reduced by 66%.
wood-stove-wall-clearances-primer.147785
 

Scorpiorias

New Member
Sep 22, 2019
3
PA
Free standing stoves radiate in all directions. A Fisher Fireplace Insert radiates from the front half that protrudes from the hearth, and the back has an air chamber around it which uses convection heat, which is heated air blown into the room with a blower. This extracts the heat from the Insert instead of being absorbed into the masonry. It was thought by using the mass of a fireplace, the heat would radiate into the building. The problem is that it also radiates out the back, and up through the roof, defeating the purpose of heating the mass.

The reason you don't want to enclose a freestanding stove, is due to warping the side and rear sheets due to uneven heating.
As the stove radiates heat off of it, this keeps the surface temperatures equal all the way around. When placed in a fireplace or alcove, heat radiates off the front more than the sides or back. When the enclosed rear stays hot, and the front cools, it creates problems. This uneven heating was the cause of warped sheets, cracked welds, and one of the few reasons for any warranty problems.

Cement blocks do not take well to extreme heat. They break, crack, and break down if not protected by a firebrick covering or liner. Basement walls are prone to cracking behind these stoves as well during extreme cold outside.

You must have a Series III Grandpa? (it will have a UL label on the back) to quote 39 1/2 inch clearances. That is to the rear, 42 inches side.
For reduced clearance to combustibles you can build a UL approved heat shield with cement board and face with tile, brick or stone. Reduced clearance is then reduced by 66%.
wood-stove-wall-clearances-primer.147785
Much thanks to you coaly. I have decided to instal the stove in the middle of a room. It makes the stove the center piece of the room, that way it can be sat around, and I won't have unusable spaces just for clearance! In essence, a woodstove that doubles as a coffee table.
Anyway, I am looking at ordering my pipings from plumbersstock. Double wall duratech chimney/ Duravent stove pipe. Seems like plumbersstock has the most competitive pricing on the web. However, it takes 4 to 5 weeks to recieve. I am looking to do this on a budget and timely. Any suggestions will be appreciated.