What to do about flue? Remove it? Ovalize liner to fit? Please advise.

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clydesdale

Member
Mar 8, 2016
171
New York
I am getting closer to getting an FPX Large Hybrid insert. I am going with an insulated liner, a block off plate, and am having an outlet put in the fireplace for the blower. What I don't know what to do with is the flue. The 6 inch pipe certainly won't fit in there. So, do they bust it out, or what is the proper method of handling this? Thanks.
 

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The OP mentioned installing a block off plate so that link could be handy but I believe his question is actually about how to get through/past the damper. Yes a liner could be ovalized if there's room or the damper can be removed or cut out to accomadate the liner.
 
What are the inside dimensions of the flue?
 
I figured he was actually asking about the damper, because the picture clearly shows a damper and no flue measurements were given. But yes if it is actually fitting the liner down the flue and you're wondering about busting out tiles, inner measurements of the clay flue tile would be needed to advise on that.
 
Not sure putting an outlet in the fireplace is a good idea, there's a lot of btu's in there
 
Not sure putting an outlet in the fireplace is a good idea, there's a lot of btu's in there
it also does not meet code because you have to be able to unplug the unit in the room it is in
 
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Thanks guys. The damper measures 5 3/4. The inside of the clay chimney seems much larger than that, but I can't reach up there to get a measurement. How much room will a 6 inch insulated liner need? Can that be ovalized?
I can probably cut the back side of the damper more. The front side is pretty much right up against the masonry.

With regards to electric. The wire will be pulled up from the basement and then hardwired to the fan with the manufacturers hard wire kit, no outlet box.
 
Probably have to remove the damper and 2-3 rows of brick from the smoke shelf. i just cut the hinge pins on the sides of mine and removed 2 rows of brick from the center. You'll need to get behind the smoke shelf and vacuum all the years of chimney cleaning out of there as well. Careful cutting to much off the front or into the lintel . That's your support.
 
[QUOTI ="rwhite, post: 2122357, member: 19611"]Probably have to remove the damper and 2-3 rows of brick from the smoke shelf. i just cut the hinge pins on the sides of mine and removed 2 rows of brick from the center. You'll need to get behind the smoke shelf and vacuum all the years of chimney cleaning out of there as well. Careful cutting to much off the front or into the lintel . That's your support.[/QUOTE]
Wow, I may have to remove brick? Ugh. I think I'll put an inspection camera back there. Removing brick sounds a little scary, but I don't know how it is constructed. Maybe they will just pop out with a hammer and chisel.
 
Depending on the type of brick I suppose it could be a bit difficult. Mine were just standard clay. I just used an air chisel and they popped right out. I removed 3 bricks from the top row and 2 from the 2nd row in the center. Gave me plenty of wiggle room with the liner. You'll probably going to need an angled SS adapter as well. Very rare are they a straight shot to the outlet and that flex liner doesn't do sharp S bends.
 
Bricks are not hard to come off, just get between the mortar joints and they come right off
20160824_194520.jpg

This pic shows the damper bracket in place but I had to cut it off, in my case I had to take two rows of brick off
20160828_144434.jpg

I first took off one row but the liner would not come through because of the angle so I had to take off one more row
 
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OK, I had an installer come today and if I want an insulated liner, he believes we will need to remove 2 rows of brick. I have been reviewing the how to make a block off plate thread and I have a few questions. I will have to fabricate this mostly the day of the install. How can I make this as ready for the pipe as possible? Does anybody have a link to the horseshoe method? Any idea how large the outer diameter is for the 6 inch insulated pipe?
 
Installed mine without a block off plate for now, I plan on making it in two pieces so I can get it in without messing with the liner
 
Well the insulation typically stops above the block off plate. But you cant cut the hole till you know exactly where that liner is going to be. And you cant do that till the stove is in place
 
OK, I had an installer come today and if I want an insulated liner, he believes we will need to remove 2 rows of brick. I have been reviewing the how to make a block off plate thread and I have a few questions. I will have to fabricate this mostly the day of the install. How can I make this as ready for the pipe as possible? Does anybody have a link to the horseshoe method? Any idea how large the outer diameter is for the 6 inch insulated pipe?
If your paying for install a plate shouldn't add to much to the bill. Maybe just have them do. that way when it's buttoned up your done.
 
Neither of the two installers usually make a plate. One is going to look it up to see what it is. So, i may need to carry the ball most of the way. Can i make the solid plate and just leave off the hole until that day?
Or, would I be able to add the plate after the install? Could I just make a two piece plate, such as two horseshoes that wrap around the liner?
Will I have access with the surround panel removed?
Is 24 ga. galvanize steel the way to go? I think I have to order that online. Any advice where to purchase? Thanks guys. You all have been a tremendous help.
 
I just made my ghetto block off plate this last weekend. I used a piece of galvanized that was meant to be used for return air ducting. It was fairly reasonable and readily available at the hardware store. Having just put mine in. I'd say in my instance it would not have been possible to install after the insert was in place. Mine isn't sealed and I built it in two pieces. I didn't seal it because I'm insulated top to bottom and I stuffed the smoke chamber/shelf with roxul and it's an interior chimney.
 

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Neither of the two installers usually make a plate. One is going to look it up to see what it is. So, i may need to carry the ball most of the way. Can i make the solid plate and just leave off the hole until that day?
Or, would I be able to add the plate after the install? Could I just make a two piece plate, such as two horseshoes that wrap around the liner?
Will I have access with the surround panel removed?
Is 24 ga. galvanize steel the way to go? I think I have to order that online. Any advice where to purchase? Thanks guys. You all have been a tremendous help.
You can do but the issue is how much room do yo have to work. No way could i get tools between my insert and the fieplace to work. I could barely get a drill in sideways to attach the adapter to the flue. I probably moved my insert in and out 3 times. Got the liner and adapter lined up then pulled it out and built the block off plate, then pushed it back in to attach the liner. I'd just hate to have you pay for an install that you have to tank back out once they leave to install a plate.
 
gonna be nearly impossible to get a block-off plate in after installation without removing the insert. you'll need to get the insulated flex in place first, then put in the block-off plate. Many installers don't want to do the plate and will tell you it is not needed, but you will get better heating performance from your insert if you put it in.
 
Don't ovalize the liner. Keep the liner round so you will be able to clean it. Ovalizing the liner makes it harder to clean.
 
OK, I have ordered the stove and liner. The liner is an insulated liner and therefore I will have to likely remove some bricks to clear the liner. The installer still thinks the block off plate is not necessary. How do you insulate the block off plate? Do you adhere the insulation to the block off plate. The installer stated that the plate has no R value and that I would be better just using Roxul. But, I believe you insulate the plate, correct?
 
As far as install, after the liner is in just stuff/fill with Roxul as much as you can above where the plate will go. The plate will stop air movement, (something Roxul alone will not do), reflect heat and stop Roxul from falling out. Also keeps fibers from getting into room.

Make the plate now and prefit it then wait until the installer is on site to cut the hole. This way you'll know exactly where the hole should be. Once the liner is down stuff with Roxul then fit the plate in and fill the gap between the liner and plate with Roxul. Leave the hole big enough to move the liner around some so the installer has some wiggle room. I left about 1/2-3/4" all around.

You can probably precut some of the Roxul too. Stuffing it around the liner will most likely be done with pieces but the last couple layers just above the lintel were nice full sheets cut to the shape of the upper firebox w/ hole for liner. Roxul holds its shape well so made for a nice job.
 
Many installers will not want to deal with a block-off plate due to the difficulty in getting it in properly, so they will tell you it is unnecessary. The simple fact is that you will get better performance (more heat retained in your home) with it, than without it.

Insist on the bock-off plate - you won't be sorry you did.

Also cut out the damper using a 4 1/2 inch angle grinder with a cut-off wheel, and yes you may have to break out some fire brick in the top back side of the fire box to get the liner through without denting or ovalizing it. It is fairly easy to do.
 
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