1982 Fisher Wood stove

[Irish3330]

Hi, We bought an older house with a 1982 Fisher Grandma bear/Teddy bear wood stove. It has the metal plate still on the side giving the info about it. I was wondering if you need a metal grate in it or not. Im hearing no, but there is one in it that looks like it has been used a lot. Also what's the best temp to run the stove out to heat up the house? Thanks for all your help!

 

[coaly]

No grate in a wood stove. This allows excess oxygen under the logs to burn fast and prevents the close proximity of coals to heat the new load of wood for the next fire.

Fireplaces are designed to burn fast and hot for the masonry mass to absorb the radiant energy and radiate into the room over time. So grates are used to raise the wood in an open fireplace.

Always burn on an inch of ash for many reasons.

Use a pipe thermometer to maintain the correct flue temperature. This will depend on many factors. Start with what stove model you have, (so I know what size outlet the stove has. GM 8 inch - Teddy Bear 7) and what type chimney, (Factory Built insulated, masonry, interior/exterior, and importantly the pipe configuration and flue diameter) This determines the minimum flue temperature required to prevent creosote. Then you can open air more if necessary for more heat, but a shorter duration fire.

 

[Irish3330]

Thank you for your help. I appreciate it!

 

[Gordievs]

No grate in a wood stove. This allows excess oxygen under the logs to burn fast and prevents the close proximity of coals to heat the new load of wood for the next fire.

Fireplaces are designed to burn fast and hot for the masonry mass to absorb the radiant energy and radiate into the room over time. So grates are used to raise the wood in an open fireplace.

Always burn on an inch of ash for many reasons.

Use a pipe thermometer to maintain the correct flue temperature. This will depend on many factors. Start with what stove model you have, (so I know what size outlet the stove has. GM 8 inch - Teddy Bear 7) and what type chimney, (Factory Built insulated, masonry, interior/exterior, and importantly the pipe configuration and flue diameter) This determines the minimum flue temperature required to prevent creosote. Then you can open air more if necessary for more heat, but a shorter duration fire.

Hello Coaly,
I have just moved into my own place and among the countless projects I’ve had, getting this stove up and running was one of them. I’m just curious if you have the time to help me out with any advice you have.

I’ve recently been looking at other forums and manuals in regard to this stove, it’s original to the house, built in 1982 and was the primary heat source for it and likely will be for me as I’ll take the time to split wood instead of spending money on heat.

I believe this is a ‘76 Grandma Bear stove. There’s only one hole for the stove pipe on the top nothing on the rear, it’s a 6” hole.
Approximate measurements:
Width of top plate: 25”
Depth from rear leg to ash plate: 28”
Height to front of top plate:25.5”
Height to rear of top plate: 31.5”

I’ve been trying to piece together all of the information I’ve seen you posting about it but I figured I’d come directly to you as you are a wealth of knowledge on the topic.

I have some photos attached to show you better.
Thank you for reading and any assistance is greatly appreciated.

 

[coaly]

Grandma I from 1976. The welded plate across the back is not normal. Perhaps this had a 8 inch rear vent, or possibly cracks around the rear vent , and someone closed the back and added the 6 inch top vent? You would be able to see the original 8 inch opening in rear wall from inside.

The baffle inside was added as well. This stove had no baffle.

Does the 6 inch outlet pipe extend down into stove 3 inches inside? They should be about 2 inches exposed outside, 3 inches inside.

 

[Gordievs]

Grandma I from 1976. The welded plate across the back is not normal. Perhaps this had a 8 inch rear vent, or possibly cracks around the rear vent , and someone closed the back and added the 6 inch top vent? You would be able to see the original 8 inch opening in rear wall from inside.

The baffle inside was added as well. This stove had no baffle.

Does the 6 inch outlet pipe extend down into stove 3 inches inside? They should be about 2 inches exposed outside, 3 inches inside.

About 7” sticks out from the top and its drops into the stove about an inch. Also maybe the rear vent is covered by the fire bricks but I didn’t see it so maybe the entire back panel was replaced.

 

[coaly]

Yeah, that’s not what the drawings call for at all. The outlet pipe was cut 5 inches long, always extended inside 3 inches also specified in drawings. There was no visible welded seams.

 

[Gordievs]

Yeah, that’s not what the drawings call for at all. The outlet pipe was cut 5 inches long, always extended inside 3 inches also specified in drawings. There was no visible welded seams.

Do you think those adjustments will change how to burn it at all? And if not, is the typical burning temperature around 300-600° at the stove pipe? My stove pipe is about 15” then an elbow into a masonry chimney

 

[coaly]

The baffle patented as the “Smoke Shelf Baffle” was installed in this model of the UL Listed stoves with a III designation. It goes all the way across. The pipe extending down allows hot rising gases to contact the top before being scavenged down and up the stack.

Magnetic thermometers read surface temperature, which is about 1/2 internal flue gas temperature. The object is maintaining minimum 250* to the top before exiting while smoke is present.

The creosote zone below 250 is actually about 500 internal, assuming cooling back down to 250 at top. This is only a guide since all venting systems cool differently.

The hot zone, about 500f on a pipe thermometer being 1000f internal is the high constant operating temperature of Class A Chimney and liners.

Adjust air after fire is established to stay above the critical lower zone to prevent creosote and below the hot zone to prevent overheating chimney.

 

[Gordievs]

The baffle patented as the “Smoke Shelf Baffle” was installed in this model of the UL Listed stoves with a III designation. It goes all the way across. The pipe extending down allows hot rising gases to contact the top before being scavenged down and up the stack.

Magnetic thermometers read surface temperature, which is about 1/2 internal flue gas temperature. The object is maintaining minimum 250* to the top before exiting while smoke is present.

The creosote zone below 250 is actually about 500 internal, assuming cooling back down to 250 at top. This is only a guide since all venting systems cool differently.

The hot zone, about 500f on a pipe thermometer being 1000f internal is the high constant operating temperature of Class A Chimney and liners.

Adjust air after fire is established to stay above the critical lower zone to prevent creosote and below the hot zone to prevent overheating chimney.

Seriously a life saver! Thank you so much for all the help!!