insert in a zero clearance fireplace

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ssupercoolss

Member
Hearth Supporter
Jan 28, 2008
223
southeast pa
probably been beaten to death here, but i would like some info on a insert in a zc fireplace. from what i have read so far on here, it can be done, must make sure it is an insert designed to go into a zc. right now, i guess i just dont understand how you connect the insert to your existing chimney. maybe a little background will help. this is for my mountain house, built sometime around 1973. there is an 8" metal double wall chimney enclosed in an exterior chase.

i take it you leave the existing fireplace intact, and install the insert into it?

still really confused how you connect it to the chimney. once you slide in the insert, is there enough room above it to get your hands in to do whatever?

maybe a liner down the chimney?

i really have to take a look at the financial aspect of this. this is a weekend home, heated by ultra efficient electric baseboard heat, and if you havent heard, PA's rates are going to go up a little. the fireplace actually does ok, i actually fabbed out a blower grate type of thing that throws some hot air into the room. definetly not high on the efficiency chart, but the fireplace is always going when everyone is there, so might as well take advantage of a little extra heat. she can gobble up the wood though. hopefully there is a picture below to help illustrate some of this. i am open for suggestions....and i always like to do some research before diving in head first. thanks
 

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<>probably been beaten to death here, but i would like some info on a insert in a zc fireplace. <>

For the most part, I don't believe you're gonna be happy with WBFPI in a ZC...
First it'll be tiny & second, your ZC box is made out of sheet metal & won't support the weight of a plate steel Or CI box.
Regency DOES make a Hearth Heater (H2100) that is designed to mount in front of the ZC box & vent - WITH AN INSULATED TEE LINER KIT - thru your existing flue.
The ZC chimney system is not rated for the high burn temps of an air-tight stove/insert.
It takes up room on your hearth & requires an additional 16" of hearth protection to be installed in front of the glass...
IIRC it's either 70 or 75K BTU...
It's either that or a woodstove in front of the ZC with a block-off plate to hide the existing opening...
 
If you find an insert with the location of the flue that lines up with the current ZC flue, then yes, (and yes you use need to use a liner inside the current 8" flue pipe) you can install an insert.

I have a monster of an insert in my ZC fireplace. It all lines up (I looked for one that would) and it has the feature of being able to install the flue/liner connection from inside the inserts firebox. This was the only way I could be able to make my connection as well.

Liner goes down the chimney, insert collar installed on liner, block off plate installed, furnace cement as needed, slide insert in, open insert door, reach in connect flue collar (that is attatched to the liner) to insert, level things out. Done

As far as weight is concerned, I have done nothing special to reinforce things, and no problems. KD
 
Have a Lopi Revere installed in a E-42 Heatilator fireplace with liner,,, Cost around $2,500 to install...
 

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I have the Country ( now Lennox) C160 in my ZC Majestic. Full stainless steel liner down the chase hooks up to the insert
 

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Hey, velvetfoot

<>You're pretty sure about all that?<>

Based on the products we sell, yes, but based on the pix that showed up after my post, I can see that there are more out there than I've run across...
The owner of Best Fire just took on the EF line & I will admit that I don't have the knowledge of that product - yet...
If they (and others) are workable with ZC units, I stand corrected & will attempt to learn more about them...
I DO know that we will not install an uninsulated liner into a ZC chimney system based on the temperature ratings...
PTOOEY! My foot tastes terrible ! :red:
 
DAKSY said:
Hey, velvetfoot

<>You're pretty sure about all that?<>

Based on the products we sell, yes, but based on the pix that showed up after my post, I can see that there are more out there than I've run across...
The owner of Best Fire just took on the EF line & I will admit that I don't have the knowledge of that product - yet...
If they (and others) are workable with ZC units, I stand corrected & will attempt to learn more about them...
I DO know that we will not install an uninsulated liner into a ZC chimney system based on the temperature ratings...
PTOOEY! My foot tastes terrible ! :red:

from what ive been told a zc is usually connected to a UL 130 1700 degree rated flue system , an epa wod insert usually requires UL103HT 2100 degree flue system so i believe daksy is correct in not doing installs without insulated liner.
 
We put wood inserts into ZC boxes all winter (and summer) long. The Quad 2700i fits nice and was actually made for that purpose. Just make sure you get a fully insulated liner.
 
awesome - thanks for the info guys...i will continue to look into this further, i guess in need to get some measurments of my current fp now. let me ask this question - are there any brands that i should definetly stay away from? i.e bad experienses with them?

oh - and i take it i need one with a 6" flue in order to reline the existing 8" with insulated flex?
 
The liner my dealer put in wasn't insulated.
The fireplace came with SL300 venting.
Hopefully, it'll be okay.
I don't understand why the Quad 7100 uses SL300 alone; it's gotta get pretty warm.
 
velvetfoot said:
The liner my dealer put in wasn't insulated.

Same here, dealer said I did not need one due to our somewhat mild climate and my short liner run length
 
Quad 3100i here in an older Zero Clearance fireplace with insulated liner down the 9" double wall fireplace chimney. Works great, heats well (sometimes too well) and hasn't given me a bit of trouble as far as operation is concerned. I do wish my chimney were a little taller on warmer days and that my rain cap had a removable screen, other than that no complaints.
 
I have a Jotul Castine run into a zc with the wall and zc covered with 3m faux stone. My liner is insulated but for draft not safety. If you have an air cooled system you put a 2100 degree liner inside a 1700 degree ss 8" pipe surounded by cooling air and then both pipe liner and cooled air are enclosed by the 3rd 12" pipe. It would take a lot to get through all this I would think. All Jotul stoves and most if not all inserts are rated for use with zc fireplaces.
Joe
 
Anyone with an insert into a ZC box where the liner is not insulated is at risk of lumber surrounding their prefab pipe starting on fire IF there is a massive chimney fire, or the unit is run full bore for long periods of time.
 
jtp10181 said:
Anyone with an insert into a ZC box where the liner is not insulated is at risk of lumber surrounding their prefab pipe starting on fire IF there is a massive chimney fire, or the unit is run full bore for long periods of time.
ARE YOU SURE ABOUT THAT?????????? Had the inspector out here and he passed mine!!!!!!!! My liner is not insulated.. We have had some good members banned about this subject and no one has a good answer.. Let's get the right answer on the ZC BOX ONCE AND FOR ALL!!!!!!!!!!!!!!!!!!! Please before some one's house burns down, or ask other members to come back since they were right!!!!!!!!! JMO................ Need an answer which is the truth...
 
jtp10181 said:
Anyone with an insert into a ZC box where the liner is not insulated is at risk of lumber surrounding their prefab pipe starting on fire IF there is a massive chimney fire, or the unit is run full bore for long periods of time.
I beg to differ. ZC's have air cooled chimneys and pass through boxes. What you have is a 2100 degree liner surrounded by a 1700 8" pipe surrounded by circulating cooling air all encased by a 3rd 10"-12" galvanized pipe. Jotul corporate says this is totally safe. The bldg. inspector concurs as does the chimney manufacturer and the ins. co. In fact if done correctly this is propably safer than most other conventional installs. I have run this set up at 600-700 degrees for 10-12 hours and then gone into the attic where it passes through with an IR thermometer. The temp on the pipe was only 110-120 degrees and you could put your hand directly on it with minimal discomfort. It would take a helluva fire to pass through 3 pipes and a cooling air barrier. If this install was unsafe I'm sure one of the worlds largest stove manufacturers (Jotul) and our states largest stove dealer would not openly endorse the practice. Oh ya lumber should never surround a pipe anyway it would only surround the pass through with approved clearances.
 
I called both Quadrafire and Heatilator about installing a 2700i insert into a Heatilator E36 prefab fireplace.

Quadrafire stated the fireplace must be UL-127 listed and the liner must be insulated.

Heatilator simply stated that an insulated liner must be used.

So for SL300 chimney pipe. air cooled 1700°, you do need an insulated liner per the manufacturer.

Aaron
 
I have not met many inspectors who know much about gas/wood/pellet fireplaces. Most of them are asking us if stuff is done right.

Lets get one thing straight first, the only way a SS flex liner meets the UL 1777 listing is with the insulation. Yes I know this listing is designed for masonry chimneys. Here is a quote from a Quadrafire manual.

(broken link removed to http://quadrafire.com/downloads/installManuals/man_2700i.pdf)
"If the chimney is not listed as meeting HT requirements, or if the factory-built fireplace was tested prior to 1998, a full height listed chimney liner must be installed from the appliance flue collar to the cimney top. The liner must meet type HT requirements (2100ºF) per UL 1777."

A standard flex liner does not meet UL 1777 unless it has an insulation wrap.

Also many installs are done in which the air cooling system is blocked or disrupted.

When lining air-cooled factory-built chimneys:.
• Run chimney liner approved to UL 1777 Type HT requirements (2100 degrees F)
• Re-install original factory built chimney cap ONLY
• DO NOT block cooling air openings in chimney
• Blocking cooling air will overheat the chimney


I have personally spoken to someone who visits fire scenes regularly. He has seen many house fires caused by improper installs of wood inserts into ZC fireplaces.

Ok, Jotul... here is a direct quote from thier 350 Winterport manual. (The forum has an issue with URLs with spaces so copy/paste the link if you want to see the full manual)

(broken link removed to http://www.jotul.com/FileArchive/Technical) Documentation/Wood inserts (USA)/Jøtul C 350 Winterport/Manual_C350_Winterport_138376_RevE_1108.pdf
Installation must include a full height listed chimney liner meeting type HT requirements (2100F) per UL 1777 (U.S.) or ULC S635 (CAN). The liner must be securely attached to the insert flue collar and the chimney top. Do not block off the flow of air between the prefabricated chimney walls.

Notice the mention of needing to meet UL 1777. Now does anyone want to argue about the UL 1777? See the duraflex catalog. (broken link removed to http://duravent.com/pdf/catalogs/duraflex.pdf)

I would copy/paste but they have thier PDF copy protected. Basically it says the only way the liner meets UL 1777 for wood inserts if with the insulation sleeve.

And another quote from the VENTINOX install guide

VENTINOX® liners venting solid fuel heaters must be installed with a minimum of one inch of TherMix® or with a double layer of ProFoil or Flexwrap insulating blanket between the outside of the liner and the inside of the masonry shell to meet the requirements of UL1777...
 
Just a little tid bit: Also with the air cooled double wall pipe (like the sl300), you need to make sure the opening at the top of the pipe (at the chimney cap) is to remain open to allow the heat between the two walls to escape.

When installing a block off plate up there or a cap, or whatever, that gap should not be covered, AND, care needs to be taken when cleaning the chimney that the creosote chips and flakes don't fall down into that gap. While a little bit should not be a problem, over time a build up could be an issue.

I suppose some good stainless screen material would work well, or use the approved type of cap which is designed to allow this heat to escape and not let the junk fall into that gap. I purposely bought the cap made for the sl300 pipe just for that reason. Just a little FYI I discovered when messing with my own install. KD
 
kd460, you must not have read my very long rant (can't blame you). I actually mentioned that in there. Stating it again does not harm though because this is a critical step. Quadrafire has actually added this to their manual and went so far as to state the original chimney cap MUST be put back on. This basically leaves out any confusion as to what is safe and whats not. If you modify the original air cooled chimney SYSTEM, it becomes unknown and untested, thus unsafe.
 
"Also many installs are done in which the air cooling system is blocked or disrupted.

When lining air-cooled factory-built chimneys:.
• Run chimney liner approved to UL 1777 Type HT requirements (2100 degrees F)
• Re-install original factory built chimney cap ONLY
• DO NOT block cooling air openings in chimney
• Blocking cooling air will overheat the chimney "


http://www.heatilator.com/products/accessories/termcaps.asp


YEP! I just gleaned it over :) and your right, it is worth mentioning again. I kind of fell across this issue by accident during my install. The only reason I recognized it was thru an obscure mentioning of it in a post long ago and when I switched out caps I knew exactly what the poster was talking about. I changed form the st375 cap to the tr344 cap. It is easy to not recognize the issue unless your aware of it, especially the part about build of creosote chips and junk falling in there. Even with my proper cap (proper venting cap), I chose to put some additional screen mesh over the venting portion, as it seems a natural place for creosote and junk to fall into it as it flakes off. Idid this based on my installation situation and others may be different.

Some of the liner kits out there that include the cap would cover the "venting feature" of the sl300 pipe and could lead to problems (maybe you mentioned that also...) KD
 
I still think it's interesting that the largest wood burning unit that Quadrafire sells, the 7100, uses the SL300 chimney system alone, and that the smallest woodburning unit, the 2700i, requires an insulated liner through that same SL300 system.
 
Its just the way it was tested. A 2700i could prob be safe if tested as a system with SL300, but its not tested that way so its an unknown. The inserts are tested to work with any compliant liner, and the built in units are tested as a full system with a specific pipe.
 
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