Fisher woodstove troubleshooting

[Jen1975]

Hoping someone can help me - we bought a house and it looks like we have a Fisher Grandma wood stove. We’re having an issue with smoke in the house and I’m trying to troubleshoot. It’s vented on the top, but it has a round hole at the back. The 5th pic is inside, the box is around the back hole but it is open on top. Is it just me or did someone actually put this together wrong?! If so, is there anything we can do to make it work as is?

 

[coaly]

For wood burning, remove the damper on the back. It is an air INTAKE for the chimney to control draft. It should not be used burning wood since it will allow indoor air into the chimney to cool it. That is what it is for. However during a chimney fire, it will OPEN to allow air into the chimney feeding the fire in the chimney. It is fine for coal use only. Remove and cap it with a metal stove pipe cap.
Install a flue pipe damper in the first section of straight pipe.

Use the search feature at top right and search "barometric damper" within this Forum for more information and how they work.

And welcome to the Forum! It is put together correctly, so it's you . I'll explain correct operation and when you understand the principal of what makes a stove work, things will come together.

 

[coaly]

To address the smoke issue in the house, make sure the horizontal connector pipe is pitched upward at least 1/4 inch per foot.

Make sure the chimney is clean as well as the screen at top, if equipped.

Starting a fire with paper, cardboard and kindling, open draft cap intakes (actually called intake dampers) a couple turns. As it starts, allow the chimney to heat. You should have a magnetic thermometer on the pipe just below elbow. This will give you an idea when you are operating at the correct temperature. As larger wood is put on and it catches, close both intakes down to slow the fire. 1 to 1 1/2 turns should be about right until fire is established and you can set the air dampers to control the fire you need. Once the chimney is hot inside the inner flue, the rising exhaust gasses creates a low pressure area in the chimney, connector pipe and stove. This allows atmospheric pressure to PUSH air into the intakes. Any leak will also allow air INTO the stove, pipe or chimney, not out. So operating correctly will not allow smoke inside. All leaks are air moving towards the low pressure area crated by the chimney. If the chimney is too cool (keep it above 250* to the top when smoke is present) the draft will not be strong and smoke leakage could occur. This critical 250*f. temp is needed to prevent water vapor from combustion from condensing inside the chimney allowing smoke particles to stick. This is creosote which can form rapidly when burning too cool, again when smoke is present. During the coaling stage you will have lower temperatures and no smoke particles to stick.
(your flap on the back now is an air intake into chimney and should never allow smoke to reverse the wrong direction. Mechanical fans in the house can overpower the natural draft (clothes dryers, gas or oil burner vented appliances, radon blowers, kitchen or bath vent fans - anything exhausting air to the outside)
You could close the flap and cover tightly with aluminum foil temporarily to close the barometric damper off until you get a pipe cap.

 

[Jen1975]

For wood burning, remove the damper on the back. It is an air INTAKE for the chimney to control draft. It should not be used burning wood since it will allow indoor air into the chimney to cool it. That is what it is for. However during a chimney fire, it will OPEN to allow air into the chimney feeding the fire in the chimney. It is fine for coal use only. Remove and cap it with a metal stove pipe cap.
Install a flue pipe damper in the first section of straight pipe.

Use the search feature at top right and search "barometric damper" within this Forum for more information and how they work.

And welcome to the Forum! It is put together correctly, so it's you . I'll explain correct operation and when you understand the principal of what makes a stove work, things will come together.

Thank goodness! We were worried we were going to have to get a new one! I think we will end up having to repipe it regardless, it looks like they spray painted the pipe?! Can’t see it in the pics but it definitely has that uneven look of a poor spray paint job. So, question - wouldn’t that damper on the back allow smoke into the house the way it is now? I will let my husband know it’s an (easier) fix! He will be very happy!

 

[coaly]

No.
Think of the chimney as your vacuum cleaner hose. If you have a hole in it, dirt can't leak out into the house, air leaks IN to fill the low pressure area inside the hose.

It's all about differential pressure between inside the chimney and out.The box you see inside the stove has a separation between the inlet opening where flap is and firebox. The opening for exhaust goes up the top outlet. Exhaust gasses are lighter than outside air and rise up the pipe and chimney. The intake at flapper on the back points up the top outlet. So the rising exhaust gasses in the pipe and flue that are lighter than outside air rise upward creating "draft". Draft causes the low pressure in the chimney like a vacuum. The indoor air pressure is higher than what is inside the chimney, so indoor air rushes INTO the chimney when the flap is open, or anywhere it can get in to fill the void created by chimney. This is the same as CLOSING a manual damper inside the pipe to slow the gasses rising up the chimney. This reduces draft, which slows the stove down by slowing the incoming air. A damper in the flue slows the velocity, which affects the stove. It is a chimney control. So even though your damper is mounted on the stove, it controls too much draft the chimney creates.
When the rising gasses go too fast causing too much air to rush into stove, burning too fast, too hot and wasting fuel, the flap OPENS allowing indoor air to rush into the vacuum of the chimney. The cooler indoor air cools the inside of chimney slowing the draft, in other words controlling the stove by slowing the chimney. Air pressure is greater outside the stove and chimney, so air only leaks IN where it can. (air intakes or barometric damper)
This is why operation keeping the chimney hot is needed to keep the stove going and prevent smoke coming in when opening door to load stove. When the chimney is hot as it is supposed to be, no smoke can come in since the pressure is greater OUTSIDE of the stove, pipe and chimney.
Operating with the chimney too cool is the most common way to allow smoke in. If the chimney is hot as it should be from proper operation nothing can leak out of the system, air only leaks IN.

You actually have a top of the line stove with the Barometric Damper option to make it more efficient. The problem arises by letting cool indoor air into the chimney cooling it too much, causing creosote in the chimney which is very flammable and is the cause of chimney fires. Removing it will not only prevent creosote, it does not allow air into chimney in the case of a chimney fire. They are used exclusively and required to keep the draft constant on coal stoves. Coal does not form creosote so they are safe with that fuel. Remove it for what you are burning.

 

[coaly]

Don't be concerned about the paint. It should be high temperature paint which cures with heat. It will change to match or need repainting at season end. Just make sure the horizontal pipe section is going up hill from stove towards chimney by at least 1/4 inch per foot. That will cause smoke to come inside.

 

[Jen1975]

Don't be concerned about the paint. It should be high temperature paint which cures with heat. It will change to match or need repainting at season end. Just make sure the horizontal pipe section is going up hill from stove towards chimney by at least 1/4 inch per foot. That will cause smoke to come inside.

Thank you Coaly! Really appreciate you taking the time to educate us. We will be getting a thermometer, cap and etc. so we can safely (and happily) run our stove!

 

[Dslusser]

Hello my name is Darin I have the same grandma fisher wood stove and I already capped off the back and I’m using 8 inch pipe. Are wood stove we are having a problem getting to much air inside and it’s making the fire burn really hot and the front drafts I can closed it all the way and it’s not controlling the fire at all. I looked up this wood stove about a door gasket and it said this one don’t not need one. I’m worried about can’t controlling it and it will burn down my house. Can you help me figure out why it’s getting to much air inside?

 

[Todd67]

Hello my name is Darin I have the same grandma fisher wood stove and I already capped off the back and I’m using 8 inch pipe. Are wood stove we are having a problem getting to much air inside and it’s making the fire burn really hot and the front drafts I can closed it all the way and it’s not controlling the fire at all. I looked up this wood stove about a door gasket and it said this one don’t not need one. I’m worried about can’t controlling it and it will burn down my house. Can you help me figure out why it’s getting to much air inside?

Welcome to the forum!

Does your stove have a gasket around the doors? Does your stove have an exhaust hole on the rear and top? Which one did you cap off, and how did you can it off? Posting pictures helps us see what might be the culprit.

 

[bholler]

Fisher doors should not need gasket. But I have worked on many that absolutely needed it. If the old barometric hole was leaking that would kill draft not make it stronger

 

[Dslusser]

Welcome to the forum!

Does your stove have a gasket around the doors? Does your stove have an exhaust hole on the rear and top? Which one did you cap off, and how did you can it off? Posting pictures helps us see what might be the culprit.

When we got the wood stove it did not have a gasket for the doors by looking at it it did not seem like one would fit. The rear and top have a hole we pulled off the daper thing off the back and caped off the hole.

 

[Todd67]

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.

 

[Dslusser]

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.
View attachment 250687

Okay do you think this stove should have gasket in the doors?

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.
View attachment 250687

okay

 

[Dslusser]

Okay do you think this stove should have gasket in the doors?
okay

We will try tonight to see if that helps drafts down. Just seem like when it was drafted down it was pulling air some how on the out side of the wood stove into the stove making it burn hotter and the wood did not last that long maybe a hour. And the draft nobs where so hot I could not turn them with out burning my hand. But yes I will try what you was talking about and see if that helps.

 

[Todd67]

It looks like your stove had a gasket at one time, and was later removed. If you suspect air is entering your stove from somewhere besides the draft caps, try leaving them closed after you get the stove pipe thermometer up to temp.

I would try to avoid putting a gasket in your door. My Mama Bear had a gasket in the door when I bought it. I removed the gasket when I restored the stove and it has been just fine for me.

I always handle my stove with thick welding gloves, not the cheap ones either. The handles and draft caps get hot.

 

[coaly]

The inside web of the channel iron which is the iron door seal doesn't look right.
It should be one color, as smooth as possible. Wire wheel the channel until clean.

When clean, no excessive play in hinges or pins, it should not need any gasket material. It has NO clearance (space between parts) for gasket material when latched against door seal. The center of channel iron makes contact on the raised portion on back of doors, and the flat portion on back of doors makes contact on the edges of the channel iron door seal. This makes a 3 point contact all the way around, and is "air-tight" as built. If anyone applied gasket cement for a door gasket at any time, the residual cement in the channel keeps the door from making proper contact at the 3 points required all the way around.

Do you have a flue pipe damper? The flue damper is a chimney control that is a variable resistance which slows the velocity of rising gasses, which decreases draft. It is used for an over drafting chimney. Closing it partially slows the air coming in.
With screen in place, this becomes your only air control as well.

You should be able to close draft caps when burning and have the fire die with little to no flames, or go out.
With them closed you may be able to hear the air whistling through the leak in a quiet house.
Otherwise, you can take a smoking incense stick and go around any places where it could leak, and you will see it rush into the stove.

 

[coaly]

The draft cap knobs will get hot if they are shut with another air source feeding the fire. There is no air moving under them to keep them cool like there should be when intake air is rushing in. They were also designed with fins to be able to open and close with your foot. Socks or shoes required.

 

[coaly]

I went to the extent of lapping stove seals one time and found it does make a difference, but the time and energy involved was not worth the little difference it made.

I was a steam locomotive mechanic and worked on many engines and boilers s well. A lot of that work is machining parts to be steam tight. That is done by lapping parts such as valves, seats, and fittings together by means of a grinding compound between the pieces, working them until they mate perfectly together. The original drawings of the doors give maximum material removal if machined smooth for a better fit. I don't know of any fabricators that machined doors or seals for a flat mating surface.
I laid the stove on its back, removed door pins and used course valve grinding compound between door and door seal. By working them in circles, and all directions, the two parts grind the mating surfaces together, called lapping. You can tell by the color where the pieces touch, and you work them together until both are a consistent gray color all the way around. On steam joints you then use finer compound, sometimes using white lead in a joint or powdered graphite. It's a time consuming process, making steam so labor intensive.

 

[Don H]

Looks like remanence of door gasket material in the seal channel. Make sure that channel is clean.

 

[Dslusser]

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.
View attachment 250687

Okay do you think this stove should have gasket in the doors?

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.
View attachment 250687

okay

Looks like remanence of door gasket material in the seal channel. Make sure that channel is clean.

thanks it looks like there is cement glue black around the out side of the seal and the inside of the seal but had a lot on the bottom of the of the seal on the door

Looks like remanence of door gasket material in the seal channel. Make sure that channel is clean.

I looked at it and I was getting air on the seal and the bottom of the doors there was a lot of black cement glue left behide I will clean up today and see if that fix it thanks for info

 

[Don H]

Okay do you think this stove should have gasket in the doors?
okay

thanks it looks like there is cement glue black around the out side of the seal and the inside of the seal but had a lot on the bottom of the of the seal on the door

I looked at it and I was getting air on the seal and the bottom of the doors there was a lot of black cement glue left behide I will clean up today and see if that fix it thanks for info

Yea, that channel mates with the raised lip moulded in the door with very little clearance assuming the hinge pins and hinge holes are not worn out. You should not be able to pull a dollar bill out easily with the door shut on it.

If the door is sloppy you have two choices; new or oversized hinge pins and ream hinge holes or use the thinnest door gasket available. The second choice in my opinion is the last resort.

Often people who buy a Fisher used and don't know better think the door is suppose have a gasket so the put one in causing the door to not seal tightly.

 

[Dslusser]

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.
View attachment 250687

Okay do you think this stove should have gasket in the doors?

I don't see a stove pipe thermometer on your pipe. It should be low on your pipe, maybe 6" above your stovetop. When you load your stove, you should open the draft caps all the way. Leave them open until your stove pipe thermometer reads 450-500. Then close your draft caps all the way. Then open them 1/4 turn, not a 1/4 inch. On colder days you might have to open them 1/2 turn. If you are stuck with green unseasoned wood, I recommend you to not burn it. But if you must, you might have to leave the draft caps open 3/4 to one full turn.

From that point on, don't worry too much about how low your stove pipe thermometer gets. I never check my stovetop temperatures. I've been running my Fisher Mama Bear like this for 7+ years and I've never had excess creosote in my chimney.

This is my stove pipe thermometer right now, after loading it this morning (5 hours ago) with seasoned pine.
View attachment 250687

okay

Looks like remanence of door gasket material in the seal channel. Make sure that channel is clean.

thanks it looks like there is cement glue black around the out side of the seal and the inside of the seal but had a lot on the bottom of the of the seal on the door

 

[Dslusser]

Thanks guys that was the problem old cement from old gasket in the door was letting to much air in so did not not draft down. But thanks you fixed my problem and questions

 

[Don H]

Good news! Enjoy your stove.