Convert ZC FP to Wood Stove (Now with Picture)

[southbalto]

I'm trying to figure out the best way to convert a Zero Clearance Fireplace set up to a wood stove.

All options are on the table including a complete tear down of the existing chimney.

A stove dealer at my local hardware store told me that as long as I observe the required clearances for the wood stove, I could drop a 6" insulated pipe down the existing class a chimney (which is used for the zero clearance FP). I could then connect the pipe using a short flexible stainless steel liner (last 4') which would run through the FP damper.

Anyone have experience doing this? It would be a relatively small stove (hearthstone tribute VC aspen...something along those lines).

Thanks

 

[DAKSY]

I'm trying to figure out the best way to convert a Zero Clearance Fireplace set up to a wood stove.

All options are on the table including a complete tear down of the existing chimney.

A stove dealer at my local hardware store told me that as long as I observe the required clearances for the wood stove, I could drop a 6" insulated pipe down the existing class a chimney (which is used for the zero clearance FP). I could then connect the pipe using a short flexible stainless steel liner (last 4') which would run through the FP damper.

Anyone have experience doing this? It would be a relatively small stove (hearthstone tribute VC aspen...something along those lines).

Thanks

You could drop an insulated liner down to a Stainless Steel Tee, then add a short section of connector to the back of the stove, if you get one with a rear-exit flue.
I believe the Tribute is a top-exit flue only, but I've been wrong before.
Are you sure the ZC FP has a Class A chimney? Most don't. They have 1700 degree rated venting & you may get into a battle with your building inspector or homeowner's insurance company...
If you're gonna tear the whole chimney out - including the ZC FP, then you could install an entire Class A chimney system, but you may not like the price...

 

[stoveguy2esw]

I'm trying to figure out the best way to convert a Zero Clearance Fireplace set up to a wood stove.

All options are on the table including a complete tear down of the existing chimney.

A stove dealer at my local hardware store told me that as long as I observe the required clearances for the wood stove, I could drop a 6" insulated pipe down the existing class a chimney (which is used for the zero clearance FP). I could then connect the pipe using a short flexible stainless steel liner (last 4') which would run through the FP damper.

Anyone have experience doing this? It would be a relatively small stove (hearthstone tribute VC aspen...something along those lines).

Thanks

You could drop an insulated liner down to a Stainless Steel Tee, then add a short section of connector to the back of the stove, if you get one with a rear-exit flue.
I believe the Tribute is a top-exit flue only, but I've been wrong before.
Are you sure the ZC FP has a Class A chimney? Most don't. They have 1700 degree rated venting & you may get into a battle with your building inspector or homeowner's insurance company...
If you're gonna tear the whole chimney out - including the ZC FP, then you could install an entire Class A chimney system, but you may not like the price...

solid fuelled ZC chimneys are all "class A" however the pipe in most cases is rated UL-103(1700F rated), rather than UL-103HT (2100F rated)which is necessary for a woodstove. if 1700F rated UL-103 you will not be able to vent with it however daksy may be right about an insulated liner(im not sure) best to check with local code official prior to pulling the first nail.

 

[wahoowad]

Southbalto -

Unfortunately you are not going to find clear guidance here (or anywhere) about using a woodstove with your ZC fireplace and chimney. You will find folks who will alude to codes, building inspectors, invalidated insurance, etc. and then you will find folks like me who vent their woodstove back into the ZC chimney and feel things operate fine. I clean my chimney myself so I am able to keep a close eye on how well it is performing. No creosote buildup ever so I am not concerned about a chimney fire exceeding the rating capacity of my double-wall pipe. I also visually inspect the interior of my chase my chimney is within to make sure I see no hotspots, etc. on the walls. My stove runs great. I get a cup of creosote dust every year when I clean it. Mine drafts fine. I'm good with all my clearances. I use a piece of adjustable length double-wall stovepipe to come out of the back of my Jotul, into a tee, the tee fits into a 6" to 8" reducer, this reducer fits into the bottom of my 8" chimney. This year I am putting in a 6" stainless liner just to be even extra safe. Search this forum for ZC and 'zero clearance' and you will have a long evening of research to digest. Then you can decide for yourself.

 

[southbalto]

Thanks Wahoowad....

I've spent a fair amount of time searching and it seems there is no consensus as to what can/cannot be done. I'm inclined to just drop the insualted pipe and connect via flex.

How did you deal with floor protection? I'm thinking of cutting out the existing 3/4' hardwood and putting down durarock w/ slate on top. What did you do?
Also, did you have to reinforce the floor at all to handle the weighet of the stove?

 

[MountainStoveGuy]

as wahoo stated, you will get a deluge of codes, and listings. He has chosen to do what he wants to do, and thats fine. Rules are rules. You either choose to play by them, stretch them, or ignore them. This is not a gray area in this industry. Its a flat, illeagle install when you hook an appliance that requires a 2100* flue to one that is listed with a 1700* flue. You make the call. Here is a thread that references some of the codes and listings.
https://www.hearth.com/talk/threads/40722/

 

[southbalto]

as wahoo stated, you will get a deluge of codes, and listings. He has chosen to do what he wants to do, and thats fine. Rules are rules. You either choose to play by them, stretch them, or ignore them. This is not a gray area in this industry. Its a flat, illeagle install when you hook an appliance that requires a 2100* flue to one that is listed with a 1700* flue. You make the call. Here is a thread that references some of the codes and listings.
https://www.hearth.com/talk/threads/40722/

Thanks for the info. So i'm clear you're saying is that, per code, just dropping an insualted 6" ss liner/flue into an existing ZC chimmney would not be acceptable (assuming it's rated to 1700).

If the existing flue for the ZC was rated to 2100 it would then be code compliant to proceed with that install? Is there an easy way to determine what the existing flue is rated to?

Thanks

 

[MountainStoveGuy]

Yes, thats what i am saying. I do not know of any ZC fireplaces that use 2100* pipe.

Parts of the issues here are that zc fireplace's need to breath. The pipe needs to breath (air cooled pipe) and the fireplace needs to breath. (air cooled box). Retrofits into ZC fireplaces usually block one or both of these safety features. Most commonly the air cooled box with inserts. Liner caps and flashings, if installed improperly will block the air cooled pipe and create a more dangerous situation. The two main concerns with ZC installs is pyrophoric carbonization, and the way the system can handle a chimney fire in the case there was one. Both issues can burn your house down.

ZC fireplace's are tested to UL103. Fireplace inserts and wood stoves are listed to UL103HT. I do not know of a single ZC fireplace that is approved to be used with a insert or stove, you will find inserts that are listed for fireplaces though.

 

[southbalto]

thanks for the reply MSG.

In my situation is the best option to tear out the existing chimney and fireplace and relpace it with masorny?

What would you reccommend?

 

[wahoowad]

The pipe needs to breath (air cooled pipe)

MSG - At the top of my chimney I can easily see the inner and outer pipe. How does the breathing happen? Meaning where does the air come from? It is open at the top - but I believe the factory design has it closed at the bottom. I have one opening at the bottom and that is just the fire venting up throug the inner pipe. Is there a flow of air or is it just ambient air from the open top?

Is it merely the air gap between the inner/outer pipe that provides this? I have a lot of pictures and stuff and do not see any kind of opening at the bottom. If it was, I suspect it would be inside my chase, otherwise it would draft like the dickens and pull conditioned air out of the house.

Thanks

southbalto - Had I known how long I was going to stay in this house I would have ripped out the ZC fireplace and chimney and replaced it with something more appropriate. I did what I did as a supposed temporary workaround for a season but life goes on and here I am still doing it several years later. If you plan to stick with a woodstove for several years you should consider doing it right and invest in the right setup. Despite feeling comfortable with what I am doing I do have nagging little thoughts late at night or if I leave loved ones at home. Peace of mind is priceless.

 

[MountainStoveGuy]

The pipe needs to breath (air cooled pipe)

MSG - At the top of my chimney I can easily see the inner and outer pipe. How does the breathing happen? Meaning where does the air come from? It is open at the top - but I believe the factory design has it closed at the bottom. I have one opening at the bottom and that is just the fire venting up throug the inner pipe. Is there a flow of air or is it just ambient air from the open top?

Is it merely the air gap between the inner/outer pipe that provides this? I have a lot of pictures and stuff and do not see any kind of opening at the bottom. If it was, I suspect it would be inside my chase, otherwise it would draft like the dickens and pull conditioned air out of the house.

Thanks

southbalto - Had I known how long I was going to stay in this house I would have ripped out the ZC fireplace and chimney and replaced it with something more appropriate. I did what I did as a supposed temporary workaround for a season but life goes on and here I am still doing it several years later. If you plan to stick with a woodstove for several years you should consider doing it right and invest in the right setup. Despite feeling comfortable with what I am doing I do have nagging little thoughts late at night or if I leave loved ones at home. Peace of mind is priceless.

Wahoo, the openings in the bottom are the vents that are on top and bottom of the zc fireplace. They are what cool the fireplace body. At the top, the air cooled pipe should be open to the outside, with a hat that the cap creates to allow air movement out of the venting system. ZC fireplaces are all air cooled (unit and chimney) and if the air is blocked, then they dont cool as well. Your installation might be fine, but as a whole, they can be installed improperly very easily. THis is why its against code to do so. To much probability for a install that cuts off the air cooling to the unit and chimney. This is of course all aside from the 103HT issues.

 

[MountainStoveGuy]

thanks for the reply MSG.

In my situation is the best option to tear out the existing chimney and fireplace and relpace it with masorny?

What would you reccommend?

No, i would recommend that you tear out your pre fab fireplace and chimney, and replace it with a EPA fireplace and chimney. The epa fireplaces and chimney use HT pipe for the most part, and will meet the 2100* rating that your looking for. No need to make a masonry chimney. The only pipe in our industry that is sub par is the cheap pipe they put on pre fab fireplaces.

 

[southbalto]

So you would recommend that I get rid of the chimney and prefab box but leave the chase intact. I could then drop a HT pipe down to the area where the stove is going.

Thanks

 

[MountainStoveGuy]

yep, that would be the correct way to do it.

 

[Stephen in SoKY]

I was faced with the same issue. I decided to completely remove my ZC fireplace and all piping. I opted for an alcove although my space isn't large enough to place my stove in the alcove, I vent my (Rear vent) stove into the alcove and up the Duravent chimney that now runs up the chase formerly occupied by the ZC vent. My ZC actually opened into the other room, I closed it off during remodel and created the alcove in my den where I wanted the stove. Here's a pic of mine under construction:

And the through the wall fan I installed to move heat to the rest of the house:

This was the original opening for the ZC now sheetrocked over showing the fan exiting to the dining room:

 

[cmonSTART]

+1 what MSG said.

Hey, once you tear it out it should be a pretty easy install.

 

[wahoowad]

Stephen in SoKY - I would love to see more pictures of your ZC demo and install. Like how your pipe runs into the alcove, how you connect, finished product, how you finished the wall where the ZC fireplace facad used to be, etc. Or anybody elses!

 

[Stephen in SoKY]

Wahoowad you have a PM.

 

[DiscoInferno]

Yes, thats what i am saying. I do not know of any ZC fireplaces that use 2100* pipe.

The Majestic WMC42 is one. It uses CFM's triple-wall air-cooled "type-S" or "S8" chimney, which is HT2100 rated and is also used for the VC Sequoia EPA ZC fireplace. I did a direct-connect with mine to vent the Fireview (see https://www.hearth.com/talk/threads/39969/). I'll line it if draft or creosote buildup proves to be a problem, but otherwise I don't see a safety issue. (Especially with the cooler flue of a Fireview.)

That said, my first foray into EPA wood heating was to remove an old Superior prefab fireplace and chimney and replace it with the Ultima and new chimney. There was no way to tell what that fireplace/chimney was rated to, or how it was installed. Turned out they filled the cavity around the fireplace with loose insulation, which is a no-no.

 

[southbalto]

Thanks again for all the helpful advice.

I talked a bit with a local dealer and he quoted me $180 per 48" section of flue (If it's a fair price I'm happy to go with him). Is there a good online alternative?

I was also considering:
(broken link removed to http://www.chimneylinerdepot.com/store/comersus_viewItem.asp?idProduct=114)

 

[MountainStoveGuy]

You can always find venting cheaper online. However, if you are picking a stove, then you can pick generic HT pipe. IF you pick a fireplace, most have proprietary pipe so you do not get a selection. If you buy venting online, you might have trouble finding someone to install it. Most installers will only install the pipe they furnish. They leave the online buyers for the DIY projects. $180 is not as bad as some, i think that same stick of duravent you linked to has a MSRP of $225.

 

[polaris]

Most all jotul stoves and a few inserts are approved for connection to ZC fireplaces. You must observe proper clearances and line it.

 

[MountainStoveGuy]

Most all jotul stoves and a few inserts are approved for connection to ZC fireplaces. You must observe proper clearances and line it.

Yes, but zc fireplaces are not approved to have inserts or stoves hooked up to them. It does not go both ways.
https://www.hearth.com/talk/threads/40722/

 

[polaris]

How could Jotul plainly state hook up to ZC is safe and provide such detailed intructions on how to do it if it is both illegal and unsafe? Seems like an unimaginable risk for such a large corp.( and a litigators dream)

 

[MountainStoveGuy]

look at NFPA 211 rules, and UL1777. Manufactures ARE taking a big risk. Your NFI courses will harp on this issue over and over. In the mean time, dig through some old ZC manuals and look where they plainly state that they will not approve liners or inserts in there appliances.