Woohoo! Finally picked up a fireplace insert!

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Member
Dec 1, 2016
107
Milwaukee
So my GF has been anti burning wood for a long time; she is a worry wart and felt that they are dangerous. Well... with covid around, and us being stuck at home for most of this winter, I was dreading our heating bills this season. After explaining we'll be home all season and how much money we can save, she finally got on board! I happened to find a deal on an Osburn 1800 fireplace insert, it's kind of interesting, it has a wrap around door with 3 piece of glass.

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!


I picked it up CHEAP, and it has a bit of corrosion where the door seals (just surface rust) and the door seal looks shot, but other than that in good shape! Dragged it home yesterday. Going to clean it up and want to install this weekend.

I've watched a few videos on installation, seems pretty straightforward, but being a total newb I have some newb questions:

1. How do you fit the pipe through the flue? I see some people grind/smash out the flue to fit a pipe. She says that's super hack.... and if you do that, do you seal the openings on the sides of the pipe with anything? Sheet metal? Insulation?
2. I've seen others try to run a flexible oval section through the existing flue. Where do you get that style?
3. Thinking about going to menards and just buying the generic class A 25' install kit. Anything else I should grab?
4. I have no surround/faceplate. It didn't come with it. I'm thinking about just drawing something up and having a metal place fab me something that really fits the fireplace well. Any pointers or is it really just 'square sheet metal piece w square cutout' simple? Does it need to be insulated on the back?
5. Do you seal the sides of the fireplace up between the insert and the firebox? I would just imagine cold air could come down the chimney when it isn't burning and shoot around the surround. Thoughts?

Thanks a bunch dudes! Going to go cut down some standing dead trees today, already have a few racks of wood ready.
 
So my GF has been anti burning wood for a long time; she is a worry wart and felt that they are dangerous. Well... with covid around, and us being stuck at home for most of this winter, I was dreading our heating bills this season. After explaining we'll be home all season and how much money we can save, she finally got on board! I happened to find a deal on an Osburn 1800 fireplace insert, it's kind of interesting, it has a wrap around door with 3 piece of glass.

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!


I picked it up CHEAP, and it has a bit of corrosion where the door seals (just surface rust) and the door seal looks shot, but other than that in good shape! Dragged it home yesterday. Going to clean it up and want to install this weekend.

I've watched a few videos on installation, seems pretty straightforward, but being a total newb I have some newb questions:

1. How do you fit the pipe through the flue? I see some people grind/smash out the flue to fit a pipe. She says that's super hack.... and if you do that, do you seal the openings on the sides of the pipe with anything? Sheet metal? Insulation?
2. I've seen others try to run a flexible oval section through the existing flue. Where do you get that style?
3. Thinking about going to menards and just buying the generic class A 25' install kit. Anything else I should grab?
4. I have no surround/faceplate. It didn't come with it. I'm thinking about just drawing something up and having a metal place fab me something that really fits the fireplace well. Any pointers or is it really just 'square sheet metal piece w square cutout' simple? Does it need to be insulated on the back?
5. Do you seal the sides of the fireplace up between the insert and the firebox? I would just imagine cold air could come down the chimney when it isn't burning and shoot around the surround. Thoughts?

Thanks a bunch dudes! Going to go cut down some standing dead trees today, already have a few racks of wood ready.
What size is your existing flue? Does your chimney have the required clearances to combustibles?
 
Welcome. I can see you are eager to get going but slow down. There's a lot to learn in order to do this correctly. That will help ease some anxiety. First thing that has to happen is to have the chimney cleaned very well including the smoke shelf area. At that point measure up the current ID of the chimney and let bholler know. He is a professional sweep.

Class A does not go inside the chimney for an insert install in a fireplace.
Question - Is this a masonry fireplace or zero clearance metal fireplace? A picture of the current fireplace and of the chimney will help.
Question 2 - How much firewood do you have already split and stacked for at least a year?
 
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What size is your existing flue? Does your chimney have the required clearances to combustibles?

How do you want me to measure it? Just width/depth? What do you mean? It's a chimney. Was literally designed for a fire... how would putting a fireproof pipe inside a chimney designed for fire be dangerous? Not sure what you mean by your second question.
 
Welcome. I can see you are eager to get going but slow down. There's a lot to learn in order to do this correctly. That will help ease some anxiety. First thing that has to happen is to have the chimney cleaned very well including the smoke shelf area. At that point measure up the current ID of the chimney and let bholler know. He is a professional sweep.

Class A does not go inside the chimney for an insert install in a fireplace.
Question - Is this a masonry fireplace or zero clearance metal fireplace? A picture of the current fireplace and of the chimney will help.
Question 2 - How much firewood do you have already split and stacked for at least a year?

I had it cleaned when I first moved in, but never used it. Okay, not class A, whatever the insulated pipe used for fireplace inserts is.

It's a masonry fireplace, lots of stone, house was built in 1958. I have a fair amount; I live in the woods and anytime I cut down a tree I stack the logs on a wood rack on the side of the house. Just added another rack today, and used the ATV to go up to the back edge of my property and grab another fairly large stack of wood. That stack was sitting on wood poles suspended above the ground with a tarp over the top half of it. I'll go take pics and measurements.
 
How do you want me to measure it? Just width/depth? What do you mean? It's a chimney. Was literally designed for a fire... how would putting a fireproof pipe inside a chimney designed for fire be dangerous? Not sure what you mean by your second question.
Yes measure the inside dimensions of the flue.

Chimneys that are used for solid fuel burning are required to have clearance from the outside of the masonry structure to combustible materials. For an internal chimney that is 2" an external one needs 1". This is because masonry is very good at transferring heat. Over time with that wood being heated over and over the wood pyrolizes lowering the kindling point untill the heat transfer ignites it. If you don't have the required clearance you need extra room for insulation on the liner.
 
Flue is ~ 20" wide and 6" deep, but metal flap bisects that opening, so it's maybe 3" on each side of the door. Could bust out the sawzall to remove that tho.

Here are some photos:

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!
 
Flue is ~ 20" wide and 6" deep, but metal flap bisects that opening, so it's maybe 3" on each side of the door. Could bust out the sawzall to remove that tho.

Here are some photos:

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!

[Hearth.com] Woohoo!   Finally picked up a fireplace insert!
Ok that is your damper not your flue. Your flue is the inside of the chimney
 
Flue is ~ 20" wide and 6" deep, but metal flap bisects that opening, so it's maybe 3" on each side of the door. Could bust out the sawzall to remove that tho.
If you had it cleaned, look at the report. That might have the chimney ID listed. Otherwise you will need to measure it to know what the best liner option is.
 
Wouldn't it just be 6" since that is the output on the insert?
The liner will be 6", but it needs to be insulated which adds thickness. There needs to be clearance for it to pass up the chimney. If the chimney tile liner is 8"x12" OD then the insulated 6" ss liner won't fit. Can you safely get to the top of the chimney and measure the ID of the clay tile liner?
 
Good. There are some other options, but there's no point in discussing them if the chimney's tile liner is large enough to pass the insulated liner easily.
 
Looked like the OD is 12"x12". ID is maybe 11.5x11.5? Hard to measure w the grate on.
Then an insulated liner will fit easily
 
So...



$400 vs $150. Why should I be getting an insulated liner? Is it worth the extra $250?

My chimney is in the center of the house, not an exterior wall. From what I undestand insulated liners make more sense for exterior chimneys due to how cold they are? Mine should be fairly warm and insulated already, except for the top section.
 
Last edited:
Also I still have all the same questions:

1. How do you fit the pipe through the flue? I see some people grind/smash out the flue to fit a pipe. She says that's super hack.... and if you do that, do you seal the openings on the sides of the pipe with anything? Sheet metal? Insulation?
2. I've seen others try to run a flexible oval section through the existing flue. Where do you get that style?
3. Thinking about going to menards and just buying the generic class A 25' install kit. Anything else I should grab?
4. I have no surround/faceplate. It didn't come with it. I'm thinking about just drawing something up and having a metal place fab me something that really fits the fireplace well. Any pointers or is it really just 'square sheet metal piece w square cutout' simple? Does it need to be insulated on the back?
5. Do you seal the sides of the fireplace up between the insert and the firebox? I would just imagine cold air could come down the chimney when it isn't burning and shoot around the surround. Thoughts?
 
So...



$400 vs $150. Why should I be getting an insulated liner? Is it worth the extra $250?

My chimney is in the center of the house, not an exterior wall. From what I undestand insulated liners make more sense for exterior chimneys due to how cold they are? Mine should be fairly warm and insulated already, except for the top section.
The second one is aluminum it won't work.

Insulation requirement is based on clearance to combustibles from the outside of the chimney. And actually interior chimneys need more clearance.
 
So...



$400 vs $150. Why should I be getting an insulated liner? Is it worth the extra $250?

My chimney is in the center of the house, not an exterior wall. From what I undestand insulated liners make more sense for exterior chimneys due to how cold they are? Mine should be fairly warm and insulated already, except for the top section.
You can't use B vent...that's for gas appliances...and its aluminum, wont hold up to wood heat temps.
And yes, need to get insulation...its as much for safety as it is for performance, maybe more.
 
Also I still have all the same questions:

1. How do you fit the pipe through the flue? I see some people grind/smash out the flue to fit a pipe. She says that's super hack.... and if you do that, do you seal the openings on the sides of the pipe with anything? Sheet metal? Insulation?
2. I've seen others try to run a flexible oval section through the existing flue. Where do you get that style?
3. Thinking about going to menards and just buying the generic class A 25' install kit. Anything else I should grab?
4. I have no surround/faceplate. It didn't come with it. I'm thinking about just drawing something up and having a metal place fab me something that really fits the fireplace well. Any pointers or is it really just 'square sheet metal piece w square cutout' simple? Does it need to be insulated on the back?
5. Do you seal the sides of the fireplace up between the insert and the firebox? I would just imagine cold air could come down the chimney when it isn't burning and shoot around the surround. Thoughts?
You don't have to do anything with the flue. You will have to cut the damper frame out. And yes you will want to fabricate a block off plate to close off the space around the new liner. Search for block off plate here there is allot ofbinfo
 
Thanks guys, will definitely look up the plate info. Right on about that first pipe, I saw that it said it was only approved for natural gas or oil, not wood. Just dropped a nut on a string down the chimney; looks like I have 13 feet from the top of the chimney, to the center of the fireplace. Really probably more like 12-12.5 once you realize the height of the exhaust on the insert. Menards seems to only sell 25' sections at a minimum. Hrm.
 
Thanks guys, will definitely look up the plate info. Right on about that first pipe, I saw that it said it was only approved for natural gas or oil, not wood. Just dropped a nut on a string down the chimney; looks like I have 13 feet from the top of the chimney, to the center of the fireplace. Really probably more like 12-12.5 once you realize the height of the exhaust on the insert. Menards seems to only sell 25' sections at a minimum. Hrm.
What is the minimum height requirement for that stove?
 
From the manual:

"7. Minimum chimney size is 6" (152mm) diameter. Maintain a 15' (4.5m) minimum overall height measured from the base of the appliance. Chimneys should be inspected to check for deterioration and to determine if they meet the minimum requirements, and be upgraded if necessary. The chimney must extend at least 3' (914mm) above the roof and at least 2' (610mm) above the highest point within an area of 10' (3m) of the chimney."

If I measure to the base of the fireplace it's probably right aroung 14-15', as the unit is right around 2' tall.