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pre fab replacement???

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by nacho, Aug 23, 2006.

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  1. webbie

    webbie Seasoned Moderator Staff Member

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    MSG, I'm fairly certain here that your suggestions are against the listings.
    Enclosed, for example, are three tidbits from the Lennox manual.

    Notice the warnings.....
    1. Do not modify
    2. Do not install inserts (a LISTED insert FOR THIS FIREPLACE may superceed this)
    3. A pic showing the framing.

    As to your idea of a stove being backed up against it, given the framing that you see in the picture, how could the stove possible meet clearances? There is wood within a few inches right behind the sheetrock.

    I agree that perhaps your idea of the stove pulled all the way into the room (with proper hearth) and then a complete class A chimney system might be OK...then again, it would not fit within a 8" and it would not have air around it. Bottom line - no one would do this - the fireplace should be ripped out along with the chimney - and then the generic class A installed.

    I am fairly certain on all this, as the manual also seems to indicate. Scary that inspectors allow this.....

    You can call HearthStone, but the real party involved is the pre-fab maker. I'm fairly certain the right person at each will say the same thing.

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  2. Shane

    Shane Minister of Fire

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    I don't see where there would be a danger if the stove did not exceed the dimensions of the fireplace itself. Though Craig is right it is technically against code and appliance listing in most cases to do that. Really though if the stove falls within the dimensions of the fireplace it would kind of act like a non-combustible wall. And if you relined the stove with 2100 degree liner with an airspace between the liner and the prefab chimney I would think it a safe enough way to do things. In my opinion the main hang up for such installations is the lack of testing. No fireplace manufacturer is going to test whether or not an insert/stove install would be safe in their appliances. And I understand, due to recent changes in testing requirements, that when an appliance manufactuer tests their inserts for ZC installation they have to test individual models of ZC fireplaces rather than simply granting blanket approval for installation in ZC's.
  3. webbie

    webbie Seasoned Moderator Staff Member

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    Shane, this is more than just a technical call.

    Since when did wall protection only have to be the size of the stove? In my experience, it has to be vastly larger!
    Although field experience may be helpful, this IMHO is not one of those "field calls".

    Whether it is possible to do it somewhat safe is not what I am getting at. It is definitely one of those "Pandoras Box? things that, if you start doing, will result in trouble. For example, two Pros right here in this thread have said:

    1. Some people just use a 6-8 adapter and hook to the existing chimney
    2. As long as the stove is not bigger than the fireplace face, it should meet all wall protection clearances.

    Now, you can only imagine what a DIY person or someone a couple of "whisper down the lane" ears away from a pro would do. For example, the next step is using slip-in inserts in pre-fabs (which I have seen).

    And even faceplates that seal off the fronts and just let the smoke go from there.....

    Again, I may be wrong, but I don't think this is even a grey area or open to interpretation. I think it is clearly not allowed by any code, manual or listing....

    Now, certainly it beats a single stovepipe out through the wood paneling or window. But until I see otherwise, I say it is 100% wrong....
  4. elkimmeg

    elkimmeg Guest

    I will repost codes concerning the issues There are a couple of standards involved One is a lesser requirement for just open fireplace burning UL 127 which will allow up to 1700 degrees. Wood stoves / inserts need to meet HT requirements of Ul 103 above 1800 degrees Ht is 2100 degrees


    Fireplace Insert Usually a retrofit to improve fire place effeciency, a fireplace insert might be installed in a factory built fireplace installation. Manufactures instructions may include prohibiting of any fireplace insert unless tested and listedspecifically for use with the fireplace. Decisions about aceptability of a fireplace insert may also include whether full relining with a UL 1777 liner system is required in order to upgrade to UL 103. I have to dig deeper, as I know there is wording and code language concerning these issues.


    Thinking about it there are two types of prefab fireplaces a radiation type and a convection type this question will keep being posted and asked time and time again I want to cut and paste exact code governing these situation them wiki them for future refference
  5. webbie

    webbie Seasoned Moderator Staff Member

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    Elk, this really is a pretty simple question - and answer. Please see the Heatilator labels below...clearly says on the listing plate and the manual not to modify or use insert.

    I don't think you will find a code, since it is a listed appliance....in other words, that is like looking for a code to tell you why a toaster can't be used as a hot tub heater! It clearly cannot, although they both are heaters. The toaster manufacturer says NO and I'm certain the hot tub maker agrees.

    So, it comes down to:
    1. Maker of pre-fab fireplace says no
    2. Maker of stove says no (exception when listed and tested).

    Exactly how the pre-fab cools itself or works is not part of the equation. Neither are UL standards. This is NOT a site specific situation.

    The reason that some inserts have been tested and listed for this use are:
    1. They are usually small or medium in size
    2. They are usually double wall so as to reduce radiant effect on the fireplace and surround
    3. They are installed back into the fireplace....in a place where heat can be dissipated.
    4. They have to be relined...in the "early days" some test labs tested and listed without a full reline, but they sent a note to manufacturers about 10 years ago saying they would not cover the "adapter" installation.

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  6. Shane

    Shane Minister of Fire

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    Ok, I'll reword that. So long as the fireplace meets the required dimension for wall protection. And you are right it is against code and shouldn't be a "field call". It is un-tested and could possibly have horrible consequences. However I stand by what I've said about the ZC installations in general not being allowed is probably lack of testing rather than being a sure fire way to burn down a house. I make that judgement on the basis that I have run into a mulititude of installations both hearth mount and inserts put into ZC's (NOT BY ME) that have functioned for years, some of them 10-20 years. Some were the scary 6-8 situations MSG mentioned alot of them relined. If it were a few I could chalk it up to luck but I'm being conservative in saying 50-75.

    From a professional standpoint I would not want to hang my tukis out there on anything that is not technically up to code nor would I bank my families safety on a "well I think it'll work". And I also try to always give good advice as I'm sure you all would have run me out of town by now if I didn't. Again for the poster of this thread and anyone else that reads it for advice I cannot stress enough that any installation you do should be in full compliance with local, state, national/international codes and/or your appliance manufacturers installation instruction. And in the case of a prefabricated fireplace you MUST take into account the listing from the fireplace manufacturer and the insert/hearth heater manufacturer.
  7. webbie

    webbie Seasoned Moderator Staff Member

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    Heck, I'm the first one to say that one should use common sense and that we could find something wrong with just about any installation. But, in this case, with dozens of listed wood, pellet and gas inserts available, why would someone install something that could not possibly meet clearances without considerable expense (large hearth, etc.).?

    The solution is already available and clear - a pre-fab fireplace insert.

    Those who really want something more should rip out the whole deal, and put a high efficiency built-in or generic class A chimney and stove in.
  8. DonCT

    DonCT Minister of Fire

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    I say rip out the ZC and install the FPX44. Depending on clearances to combustibles inside the existing chase/chimney, single wall would be cheaper. I would use double just to be safe, but will be more expensive.

    That set up would provide the fireplace look with an appliance that would actually HEAT the house instead of pulling heat out.

    There hasn't been any talk of what the budget range is. There's the cheap, possibly "illegal" install, the expensive over kill install, or the carefull balance of price and safety.

    If there's a local stove store, talk to them. See if they would do a walk thru with you and give you suggestions. Eyes on is the best! Pictures for us is good for verification and brain storming.
  9. elkimmeg

    elkimmeg Guest

    Craig MSg Shane I'm all for getting this issue solved and right. This issue with prefabs is not going away we will see simmilar post again and again. what I hope to do is produce the witten code. and start with the interpetation. This is a grey area that is two fold the fireplace and its venting system Neither could be compliant. If the manufacturer list as you have shown to suitiable for alternative usage then as an inspection I have a decission to make. if the insert is listed for prefab installation which path do I take the original manufactures listing or the insert stove listing. then it becomes a venting issue.Will a UL 1777 liner comply?

    There is a real issue concerning clearances to combustiables, knowing wood is touching as close as the stand offs. Hell in a masonry fire place fire box requires fire brick and 8" of solid masonry or 12" without firebrick. There is no way a couple of thin layers of sheet metal equals that masory. I have refused to issue any permits in doubt till all documentation is in hand. Without the manufacturer know in this instance and their listing. No way would I issue a permit. I also would require documentation of the existing chimney as to what standard it is tested and listed to? the statement well my inspector allowed it does not mean it is right only my inspector needs to rewiew the codes again and should not be approving what he does not comprehend. He should be smart enought to question such installations and require documentations to support his signature. We all make mistakes. The more intellegent ones don't continue making the same mistakes but learn from past ones.
  10. MountainStoveGuy

    MountainStoveGuy Minister of Fire

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    Luckly, this doenst come up often at my work, when it does, i will be better prepared. Sometimes logic has no place, just the rules. You would think that a ZC fireplace that would house a insert, could house a free standing chimney hook up. Thats not that far of a stretch. As far as sheet metal vs masonry, somtimes a 4 inch airspace between steel walls is a far better insulator then masonry. I completly agree though, get rid of the juck fireplace and pipe, and install products how they are designed to be installed. I think at work, i will let the intallers cross this issue. If i try to educate them, they will just blow me off. (after all im just a salesman right?) This is good stuff.
  11. Shane

    Shane Minister of Fire

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    The NFI study manual goes into this subject at some length. Basically at the end of that section they say that unless both the insert & the fireplace are listed for use with each other then the installer is taking on some liability. And Elk you are absolutely right about questioning whether or not the UL1777 liner is compliant or not because the majority of directions you read for them are geared towards masonry. As for the clearance issue I think that's one for testing. I personally would think the sheet metal in conjunction with the air space (space between the firebox and the outer cabinet as well as the airspace between the outer cabinet & the header that the standoffs provide) would offer similar heat protection to the 8-12" of masonry. There are many wood stoves that could be installed with .20 gauge sheetmetal hearths.
  12. elkimmeg

    elkimmeg Guest

    Never seen 10" of masonry burn threw ? but i have seen plenty of thin gage metal disinergtate
  13. MountainStoveGuy

    MountainStoveGuy Minister of Fire

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    but if were keeping with pure science here, r value of air vs r value of masonry...
  14. Shane

    Shane Minister of Fire

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    With direct exposure to flame there is no question which would hold up for a longer period of time. But with radiant heat being directed off of an insert, especially an insert with a convection jacket I don't believe burn through would be an issue.
  15. elkimmeg

    elkimmeg Guest

    As an inspector, part of my job is knowing the products out there being installed. So I did some research into the subject This issues is two fold the firebox and chimney
    There is no prefab chimney that can be used by a wood stove. There is a lot more going on here than placing a simple liner in it.
    one can not seal it off and not alow air flow between the existing layers. as designed A common liner does not sufice or satify code in a prefab There are two solutions remove the pipe and install a class A chimney as previously suggested OR THE HOME SAVER FACTORY BUILT LINER ADAPTER You can now reline a factory built chimney and have the liner system listed to UL 1777
    The adaptor sits on top of the double wall factory built chimney, without sealing off the airflow between the walls But the only liner system tested and listed are the Homesaver Roundflex Pro and ULtra Pro 6" diameonly with 1/2" Foil Face Flex Wrap insulation is required all top and bottom hardware is also Home saver

    Say you buy stove X and it list Ventinox or Simpson Dura vent as tested and approved for usage with that insert. Can you substitute Homesaver products? No. if the listing does not include additional language such as or equilvent UL 1777 listed liner systems is permissiable.

    Right now ther is only one approved tested and listed liner system that will Meet UL 1777 installed in a factory fireplace built chimney.

    Then again the first part of oru discussion is the insert allowed to be installed. Just about all were only designed and tested for the primary use None have optional testings and listinge of wood stove inserts applications. Some inserts are listed to be installed in factory built fireplaces Can they be installed in a factory built fireplace that is only listed for its current application? Can they be vented using the Homesavor linner system? If they do not list homesaver as being tested with the insert? Without the equilvancy of allowing any UL 1777 approved liner system the answer is no. No one should install a n appliance in a way it has not been listed or tested. The I think it will work approach compromises too many safety issues and liabilaties. That person has no right being in the business, I 've installed more than 50 this way and never had a problem is also not what should be heard? this guy just admitted of making the same mistake 50 prior times and now he wants to repeat it for your installation. My guy is well respected he's a pro, he knows what he is doing. Hopefully this true and most of the time it is. I am learning a lot from this post aand will bring some of this discussion to the attention to the code witters in our state. I am also going to include this in my next seminar to the other inspectors in my state In the end I think we should condence it an wiki it. This question will be asked time and time again. Probably 10 or more will be installed in factory built fireplaces this week non compliant, compromised personal safety of their homes.

    Please forgive spelling ect got to run off to the office no time to re read and correct
  16. Shane

    Shane Minister of Fire

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    What Mr. Elk said is pretty much what the NFI study manual says. I cannot see the manufacturers of ZC fireplaces ever going to the trouble to test inserts in their fireplaces. Again though I still stand by my first statement that not being able to install into ZC's is more of a lack of testing and listing issue than a safety issue. Really though there is no way around it, no way to absoulutely guarantee safety. Really even if you install an insert that is ZC approved with the Homesaver liner your typically still not in compliance with code if the zero clearance fireplace is not listed for use with an insert or liner system. All three must be listed for use with each other. The NFI study manual sums it up and says the only way to be 100% safe and code compliant is to refuse to install into ZC's.
  17. MountainStoveGuy

    MountainStoveGuy Minister of Fire

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  18. webbie

    webbie Seasoned Moderator Staff Member

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    We are going round and round, but it is not a grey area or open to interpretation.

    Shane and Elks last posts are correct. Numbers, codes and all that really don't apply. The listings DO apply.

    If we want to talk grey, then Shane is right - even tested and listed pre-fab inserts are often grey since they are not tested with each specific model.

    BUT, keeping in mind the real world, a listed convection insert which is tested and approved for a pre-fab can usually be installed into an existing pre-fab. This should be installed by a pro, all clearances checked carefully and flue completely relined.

    Other than that, use the pre-fab as an open fireplace or rip it out.
  19. MountainStoveGuy

    MountainStoveGuy Minister of Fire

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    And what fireplace manufacture is going to test it for a insert? So, this is intresting, like elk, i have made many mistakes on selling 2700I when i know there getting intalled in a ZC. So what now? Do i tell my customers i dont have anything for them? Send them down the street? Do you know how hard its goint to be to battle this when the allliance manual says right on the front thats its ok for ZC fireplcaes? Not that it comes up that often, maybe a half dozen times a year. They have been illeagle now for almost 16 years, and most have been converted to gas or WOOD by now. FWIW, those ZC fireplaces are listed for gas inserts or pellet inserts either. But they have a nock out for gas logs. ????
  20. webbie

    webbie Seasoned Moderator Staff Member

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    Looks pretty simple.

    That says unless pre-fab is an HT 103 (which most are NOT), unit needs relined to the top.

    It also says that any pre-fab built prior to 1998 would not be HT.

    I think it is a little misleading only because so few pre-fabs are tested to the higher temp. It is somewhat wishful thinking.
  21. Shane

    Shane Minister of Fire

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    I'm not saying there are no inserts approved for installation into Zero Clearance fireplaces. The sticking point is that you need reverse approval from the ZC manufacturer to install the insert or else you are using the ZC fireplace in such a manner that has not been tested & approved by it's manufactuer. Personally I think it's stupid. If an insert manufacturer tests and lists their appliance for installation into a ZC and the liner manufacturer tests and lists their appliance for use with a ZC and both give blanket approval like the Quad then it should be allowed.
  22. webbie

    webbie Seasoned Moderator Staff Member

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    I would not worrry about the reverse approval. If the pre-fab is in reasonable condition and the chimney is relined - and, of course, the insert is approved for such use - then OK by me.

    The reverse approval thing is just one more example of laws/codes/bibles being able to be quoted in such a way that EVERYTHING is either allowed or no allowed. This is where common sense and pro experience come in.
  23. MountainStoveGuy

    MountainStoveGuy Minister of Fire

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    Great! thatas the info i was looking for, i wasnt shure what the HT103 and all that biz was.
  24. ChrisN

    ChrisN Feeling the Heat

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    Nach, Nacho Nacho..... Is your head spining yet? Mine sure is! :gulp:
  25. webbie

    webbie Seasoned Moderator Staff Member

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    UL 103 gives manufacturers the choice (in USA) of testing to lower or higher temps:

    --quote

    1.2 The chimneys covered by these requirements comply with either a limited duration 1700°F (927°C) flue-gas temperature test or a limited duration 2100°F (1149°C) flue-gas temperature test, at the manufacturer's option.

    ----end quote

    Interestingly enough, the same standard addresses the use of double-wall insulated (class A) in masonry chimneys or other situations other than combustible:
    "Dual purpose residential type and building heating appliance type chimneys are tested enclosed and intended to be installed unenclosed or enclosed with combustible construction."

    I read this as saying that class A chimneys are meant to be use either unenclosed or enclosed with framing...NOT enclosed with masonry or metal.
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