Fisher stove warped

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JerryFree

Member
Mar 5, 2018
4
Big pool, md
ok so this is my first post to the group.i bought a grandpa bear woodstove recently for our home as the grandma bear that was in it was just a bit too small for the sq.footage(2,600 sq.ft in 1970 capecod) i noticed a small bulge at the rear with slight discoloration at the area. This is a top flu exit model that had no baffle installed when i purchased. I notice when i light the stove and get the stovetop temp up to around 650 the bulge gets bigger.once i damp the stove down with a good bed of coals all is back to normal again. Is this something i need to worry about? The stove isnt in bad shape anywhere else.thanks for the input.
 
Is there a baffle installed now? It shouldn't do that.
May take awhile for me to respond, no power or internet where I am from storms in NEPA.
 
Is this a Grandma III with factory baffle that sits on angle iron supports? If it is an added baffle it should set on the rear brick retainers preventing intense heat from the rear. I assume all firebrick are installed.
Power was restored here today.
 
No this is a standard grandpa bear no place for baffle install from factory. There is a baffle installed now about 3” above back firebrick and it extends out to the roll of the top plate
 
If you can set the baffle on the brick retainers, it should prevent more heat from the rear wall. Angle it upward at front towards the lower bend.
 
If you can set the baffle on the brick retainers, it should prevent more heat from the rear wall. Angle it upward at front towards the lower bend.
Ok. Soo this isnt an issue i need to worry about concerning replacing the rear section of the stove or anything like that?
 
No, when the steel expands, it bulges outward with no where to go sideways.
That is the principal used with temperature activated "snap" switches like fan and limit switches that click on and off with temperature change.
Positioning the baffle lower reduces the heat at the rear sheet

If this were a rear vent, you could develop stress cracks around the cut out opening, but cracks don't normally develop in the middle of a sheet.

It could have been placed too close to a cement or brick wall such as an alcove installation that didn't allow enough air flow around the back of the stove. Exceptionally close clearance does not allow the heat to radiate from that part keeping it hot as the rest cools creating uneven heating of sheets and warping. I cringe when I see people slide them back into a fireplace opening. They should be allowed to radiate in all directions.
 
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