New Fisher Stove Owner

[av8r]

Hello everyone. We closed on our house in August and I must admit one of the selling points was a wood stove in the family room. I have rented houses with fireplaces but am new to using a wood stove. I have been enjoying learning as much as I can from coaly and the other gents here on the forums.
I'll cut to the chase, my question is 3 parts:
1. I believe I have a pre-1980 GP bear, could you guys verify this please? I counted 6 firebricks across the back, measured I believe an 8 inch stovepipe, but my top plate measures 32" across?
2. I noticed there is alot of creosote and buildup in the firebox, it also was an earlier model without the baffle. Does this stove seem safe to use in the current condition? (They are predicting snow tomorrow night!)
3. Safe or not, I can tell some fire bricks will need to be replaced. Coaly what baffle solution do you recommend for the interior of the stove I have? Also would I need to use the wire brush to clean out the creosote inside and on the doors, etc.?
Thanks to all for any and all advice. Pictures attached.

 

[bholler]

Hello everyone. We closed on our house in August and I must admit one of the selling points was a wood stove in the family room. I have rented houses with fireplaces but am new to using a wood stove. I have been enjoying learning as much as I can from coaly and the other gents here on the forums.
I'll cut to the chase, my question is 3 parts:
1. I believe I have a pre-1980 GP bear, could you guys verify this please? I counted 6 firebricks across the back, measured I believe an 8 inch stovepipe, but my top plate measures 32" across?
2. I noticed there is alot of creosote and buildup in the firebox, it also was an earlier model without the baffle. Does this stove seem safe to use in the current condition? (They are predicting snow tomorrow night!)
3. Safe or not, I can tell some fire bricks will need to be replaced. Coaly what baffle solution do you recommend for the interior of the stove I have? Also would I need to use the wire brush to clean out the creosote inside and on the doors, etc.?
Thanks to all for any and all advice. Pictures attached.

The stove looks fine. But that isn't the part that is typically a problem. The problem usually comes from lack of proper clearances on the stove the pipe and or the chimney. Condition of the chimney etc

 

[Todd67]

Welcome to the forum! You do have a GP Bear. Does your stove have a gasket around the door seal, or does it show signs of ever having a gasket? It shouldn't have one but that doesn't stop some people from adding one.

Do you have a stove pipe thermometer? I wouldn't burn my Mama Bear stove without one. When I load my stove I open the draft caps all the way. Let the stove pipe get up to 450-500, then close the draft caps all the way, then open each one a 1/4 turn. Literally a 1/4 turn. If it seems like it's smoldering and not burning clean, open them all the way again, get the pipe up to 450-500, then close the draft caps, then open them a 1/4 turn. That stove pipe temp will drop, sometimes to 200. Don't worry about it. It's burning clean and putting out good heat.

 

[Todd67]

My stove pipe is sitting at 100 right now, no big deal. I'm about to load it for the night.

You might need your draft caps open a 1/2 turn, or 3/4 turn. Go in small increments until you get used to your stove. It depends on outside temp, quality of your wood and other factors.

 

[bholler]

My stove pipe is sitting at 100 right now, no big deal. I'm about to load it for the night.

You might need your draft caps open a 1/2 turn, or 3/4 turn. Go in small increments until you get used to your stove. It depends on outside temp, quality of your wood and other factors.

You really need to determine if it is a safe setup before worrying about how to run the stove.

 

[Todd67]

Absolutely! Like, is the chimney clean, etc...

I'll let him figure out if his stove and chimney are safe because I can't do that from NY. But, I can help him with how to use it safely.

 

[bholler]

Absolutely! Like, is the chimney clean, etc...

I'll let him figure out if his stove and chimney are safe because I can't do that from NY. But, I can help him with how to use it safely.

We absolutely can help him figure out if his setup is even close to safe. And there is no way to safely use a stove that is to close to the wall which from the pics it looks like his could be. But I can't tell if it is a protected wall. Also no way to operate a stove safely with a hearth that is to small or the wall pass through is wrong. Or any number of other things we can easily determine here. Yes ultimately it should be inspected by a sweep on site but we can give them some idea what to expect.

 

[Todd67]

I agree, but I'm not qualified to make those assessments, especially from forum pics. I try to limit the "advice" I give here, simply because there are members like you who do it for a living.

 

[av8r]

Thank you both for your timely replies!
@Todd67 , No I don't believe it has ever had a gasket around the door seal. It appears to be the "C channel" sealing mechanism described on other posts on this forum. I can take some pictures if you like?
-The seller actually left me two stove pipe thermometers! I have one I plan to use at the base of the stove pipe, as you have mentioned elsewhere on the forums. Where do you recommend I place the other one? I was thinking either the top of the stovepipe or the side of the firebox?
-Thanks for your advice on how to use the stove and the draft caps, as I have only played with wood stoves in the past I greatly appreciate all the advice! As far as using the damper is concerned, it appears to just be a small lever coming out of the stove pipe that can turn, like a doorknob. Is there any way to tell which way is open, and which way to turn it to close the damper?

@bholler , I took some pictures of the clearances and some measurements this morning before heading out to work. From the back of the stove to the chimney is 17". From the top plate to the chimney is 16.5". The "wall" behind the wood stove is in fact the brick chimney. The stove rests on a panel of brick that I can take measurements of if you think necessary, but there seems to be sufficient clearance and it is a good size platform the stove is resting on, roughly 4 feet wide by 5-6 feet long by my estimation.
-I have a Level 2 chimney inspection scheduled for next week(the earliest they could squeeze us in, and we called 3 weeks ago) but as I mentioned there are multiple days of snow in the forecast and I will only run the wood stove if we lose power or some such emergency; until it is deemed safe by the certified inspector. Again, I will post some more pictures of clearance as soon as I can.
-One concern that was raised by the home inspector is some of the mortar/masonry on the top of the chimney appears to be pitting or showing minor deterioration. I have attached a picture from the inspection report, I am curious what your initial thoughts are?

 

[av8r]

As promised, pictures of some clearances and the chimney.

 

[coaly]

Put a thermometer on the front of pipe or on the front of upper elbow where it dumps into chimney.
The object is to keep the inside flue gasses above 250* f. to the top of the chimney.
The cool/normal/hot zones are a general guide when used on the stove pipe. Many people also like to use one on the stove top or step top. That doesn't have anything to do with the creosote guide on thermometer. It is good for cooking or to let you know how hot the actual stove surface is to prevent overheating the stove.

The surface thermometer will read approximately 1/2 the inner flue gas temp on the outside of the pipe.
Depending on chimney flue; height, diameter, interior, exterior, masonry or insulted liner, you will have varying degrees of cooling as it rises up the chimney.
It becomes a guess how much cooling you have to the top, so an infrared thermometer reading a foot or so down from the top is the best way to determine the temperature at the top, and take note how hot it is at the bottom, so you know where to run it.

The reason you're attempting to keep it above 250* is to prevent the water vapor from combustion from condensing on chimney flue walls. This allows smoke particles to stick, which is creosote. More than 250* at the chimney top is a waste of fuel. It is only necessary to keep it above 250* when smoke is present.

Normally when a flue pipe damper is open, the handle should be straight with the pipe, and closed when across the pipe.
The damper is a chimney control that slows the velocity of rising gasses up the chimney. It is used to slow an over drafting chimney. You may or may not need to use it much, using the air intakes to slow the draft. Over use causes the chimney to cool too much, so it is better to err leaving it open than closing too much. Always remember to open it fully when opening doors to load.

If no damper is needed due to excessive draft, one should always be installed when using the double door stoves.
It is for open door burning with screen in place. (screen that mounts across door on stove) Once the fire is established, open doors and install spark screen. This is Fireplace Mode for fire viewing. Slowly close the damper until smoke forms and starts to roll in at top of door opening. Open slightly to evacuate smoke, yet slow draft retaining some heat in stove. It becomes your only air control to the fire with doors open. The stove is not considered a radiant heater in Fireplace Mode.

 

[bholler]

As promised, pictures of some clearances and the chimney.

As long as that wall is solid brick with no combustible material behind it you are good as far as clearances on the stove goes

 

[av8r]

As long as that wall is solid brick with no combustible material behind it you are good as far as clearances on the stove goes

Great thanks for your recommendation. I noticed in your signature that you are a chimney sweep, what do you think about the pictures I posted of the masonry of the part of the chimney that comes out of the roof? Is that something I should just patch up myself or is it more of a concern? Thanks for your advice!

 

[av8r]

Put a thermometer on the front of pipe or on the front of upper elbow where it dumps into chimney.
The object is to keep the inside flue gasses above 250* f. to the top of the chimney.
The cool/normal/hot zones are a general guide when used on the stove pipe. Many people also like to use one on the stove top or step top. That doesn't have anything to do with the creosote guide on thermometer. It is good for cooking or to let you know how hot the actual stove surface is to prevent overheating the stove.

The surface thermometer will read approximately 1/2 the inner flue gas temp on the outside of the pipe.
Depending on chimney flue; height, diameter, interior, exterior, masonry or insulted liner, you will have varying degrees of cooling as it rises up the chimney.
It becomes a guess how much cooling you have to the top, so an infrared thermometer reading a foot or so down from the top is the best way to determine the temperature at the top, and take note how hot it is at the bottom, so you know where to run it.

The reason you're attempting to keep it above 250* is to prevent the water vapor from combustion from condensing on chimney flue walls. This allows smoke particles to stick, which is creosote. More than 250* at the chimney top is a waste of fuel. It is only necessary to keep it above 250* when smoke is present.

Normally when a flue pipe damper is open, the handle should be straight with the pipe, and closed when across the pipe.
The damper is a chimney control that slows the velocity of rising gasses up the chimney. It is used to slow an over drafting chimney. You may or may not need to use it much, using the air intakes to slow the draft. Over use causes the chimney to cool too much, so it is better to err leaving it open than closing too much. Always remember to open it fully when opening doors to load.

If no damper is needed due to excessive draft, one should always be installed when using the double door stoves.
It is for open door burning with screen in place. (screen that mounts across door on stove) Once the fire is established, open doors and install spark screen. This is Fireplace Mode for fire viewing. Slowly close the damper until smoke forms and starts to roll in at top of door opening. Open slightly to evacuate smoke, yet slow draft retaining some heat in stove. It becomes your only air control to the fire with doors open. The stove is not considered a radiant heater in Fireplace Mode.

Thanks for all the great info @coaly . What are your thoughts on the condition of the stove? Should I attempt to clean it out with a wire wheel, and replace the fire bricks before using it? Or do you think it will be ok to use it in it's current state for the winter, then make those repairs?

 

[Todd67]

The stove and firebricks look fine to me. I've tried removing creosote with a wire wheel and didn't have much success. Getting your stove pipe temp up to 500 once every day will burn off some of that creosote. I would also put a baffle plate in your stove, 5/16" thick plate steel. Install it so it rests on the rear firebrick retainers, and angles upward in the front towards the bend on the lower top plate.

With your stove having an upper row of firebricks on the sides, maybe @coaly has a recommendation for how to support the front of the baffle plate.

Edited to say 5/16" plate steel.

 

[bholler]

Great thanks for your recommendation. I noticed in your signature that you are a chimney sweep, what do you think about the pictures I posted of the masonry of the part of the chimney that comes out of the roof? Is that something I should just patch up myself or is it more of a concern? Thanks for your advice!

Your whole chimney needs repointed. And after looking at the pics again double check that you have 36" from the stove to the walls on either side of that brick when you measure diagonally

 

[coaly]

Don't worry about the inside. Bricks are very useable. They get broken across the back when loading carelessly. It only becomes a factor when chunks are missing. The flakes of carbon and soot is from not burning nearly hot enough. It will burn off and clean up like new inside when you bring it up to 500 or 600 stove top temp.

When removing ash, always leave about an inch of ash on the bottom.

This is the 36 inches you need to make sure you have around the stove in all directions.

It's difficult to tell the size of the floor protection in the front of the stove. When it was designed, manuals called for a minimum of 16 inches from stove front to combustible floor materials. Code is now 18 inches. Your hearth pad only appears to be two bricks wide in front. If they are normal size bricks that only makes it approximately 8 inches of protection to the front. If it needs more, it's called a hearth extension, or a UL approved stove board. Even with the minimum protection, it's nice to have a flame resistant hearth rug in front as well. When opening doors, oxygen rushes in and can send sparks popping off the wood in all directions. That leaves melted burn marks in carpet. It also makes a tougher floor covering to kneel on so it doesn't wear the carpet directly in front of stove. Of course it depends on how much you will be using it. Some become the primary heat source, burning 24/7 and the area can get messy. Others use them as an emergency heat source only.

The baffle with upper bricks is best notched to fit the bricks. Make a cardboard template that will sit on the rear brick retainers and aim toward the lower bend on top. Make the space the smoke travels through no smaller than square inch area of chimney flue cross sectional area. The wider part in the front should sit on the upper brick tops. You can then shim it higher in front to adjust plate higher for final adjustment. Shim can be anything wedge shaped that is non combustible.

 

[av8r]

Your whole chimney needs repointed. And after looking at the pics again double check that you have 36" from the stove to the walls on either side of that brick when you measure diagonally

Ok that's what I was afraid of, it looks like that is an expensive job. I checked and it looks like it is only 26" diagonally from the corner of the stove to the wall, so I guess we will have to come up with something.

 

[av8r]

Don't worry about the inside. Bricks are very useable. They get broken across the back when loading carelessly. It only becomes a factor when chunks are missing. The flakes of carbon and soot is from not burning nearly hot enough. It will burn off and clean up like new inside when you bring it up to 500 or 600 stove top temp.

When removing ash, always leave about an inch of ash on the bottom.

View attachment 250923 This is the 36 inches you need to make sure you have around the stove in all directions.

It's difficult to tell the size of the floor protection in the front of the stove. When it was designed, manuals called for a minimum of 16 inches from stove front to combustible floor materials. Code is now 18 inches. Your hearth pad only appears to be two bricks wide in front. If they are normal size bricks that only makes it approximately 8 inches of protection to the front. If it needs more, it's called a hearth extension, or a UL approved stove board. Even with the minimum protection, it's nice to have a flame resistant hearth rug in front as well. When opening doors, oxygen rushes in and can send sparks popping off the wood in all directions. That leaves melted burn marks in carpet. It also makes a tougher floor covering to kneel on so it doesn't wear the carpet directly in front of stove. Of course it depends on how much you will be using it. Some become the primary heat source, burning 24/7 and the area can get messy. Others use them as an emergency heat source only.

The baffle with upper bricks is best notched to fit the bricks. Make a cardboard template that will sit on the rear brick retainers and aim toward the lower bend on top. Make the space the smoke travels through no smaller than square inch area of chimney flue cross sectional area. The wider part in the front should sit on the upper brick tops. You can then shim it higher in front to adjust plate higher for final adjustment. Shim can be anything wedge shaped that is non combustible.

Ok @coaly I will check the front clearances thank you. We will also see about getting a hearth rug for our stove.

Ok so if I understand you correctly, make the baffle as described in your post in the forums, just cut out a notch for the upper firebricks towards the back?
P.S. @coaly do you think I'm correct in my assessment that the stove is a pre-1980 GP Bear?

*Edited to say hearth "rug"

 

[coaly]

Yes, it is a pre 1980 Grandpa. After 1980 all doors are Cathedral style with arched top.
Fitting the cardboard template will show if cutting brick will work. If the brick retainer is in the way, notch plate.

 

[av8r]

Yes, it is a pre 1980 Grandpa. After 1980 all doors are Cathedral style with arched top.
Fitting the cardboard template will show if cutting brick will work. If the brick retainer is in the way, notch plate.

Ok I understand now thank you

 

[SpaceBus]

There are many modern wood stoves that can fit that hearth without modifying anything. They will produce more heat with less wood. There's nothing wrong with the Fisher stove you have, but something to consider when investing money into it. Also, a modern stove will have a glass door with a view of the fire!

 

[Todd67]

His stove installation might be grandfathered in. The stove has been used for an unknown number of years and hasn't burned the house down yet. What makes his clearances any more "dangerous" than they were when the stove was installed? It doesn't appear to have caused any damage to the walls or floor yet.

My clearances are more than code requires. But my firewood racks put my firewood less than 2ft from my stove. Oh crap, you say? That wood never exceeds 110 degrees, even after getting a new load of firewood in the stove up to 500* on the stovepipe thermometer. That rug on the hearth is a whopping 98* with the stovepipe at 500. BUT, I don't maintain a hot burn like many people recommended to me over the years. The only time I concern myself with stove temp is when I get a new load of wood up to 450-500* on the pipe thermometer. As soon as that 450-500* temp is reached, I close the draft caps, the open them a 1/4 turn. In other words, BARELY OPEN. I've been using my stove like this for 7+ years now without any issues. My cats and dog take turns sleeping on the hearth rug and behind the stove.

This pic will no doubt scare some of you...

 

[bholler]

His stove installation might be grandfathered in. The stove has been used for an unknown number of years and hasn't burned the house down yet. What makes his clearances any more "dangerous" than they were when the stove was installed? It doesn't appear to have caused any damage to the walls or floor yet.

My clearances are more than code requires. But my firewood racks put my firewood less than 2ft from my stove. Oh crap, you say? That wood never exceeds 110 degrees, even after getting a new load of firewood in the stove up to 500* on the stovepipe thermometer. That rug on the hearth is a whopping 98* with the stovepipe at 500. BUT, I don't maintain a hot burn like many people recommended to me over the years. The only time I concern myself with stove temp is when I get a new load of wood up to 450-500* on the pipe thermometer. As soon as that 450-500* temp is reached, I close the draft caps, the open them a 1/4 turn. In other words, BARELY OPEN. I've been using my stove like this for 7+ years now without any issues. My cats and dog take turns sleeping on the hearth rug and behind the stove.

This pic will no doubt scare some of you...View attachment 250998

What makes it more dangerous? The pyrolisis that has happened over the years of that stove being to close. It has been lowering the kindling point slowly for years. I have opened up walls behind stoves many times and it can be very scary. Yes it may be fine for years. But we just don't know. The argument that nothing has happened yet is utter nonsense and has lead to disaster many times in the past.

 

[bholler]

As far as your firewood goes yes it is to close but it is changed out all the time. No chance for pyrolis to happen. It is in no way the same as the wall behind a stove.