How important is an insert with a chimney liner?

[botbotfling]

A local dealer is selling an insert that does not require a liner that goes up the chimney. It just uses the existing chimney. The concept is that by closing off the fireplace opening and cycling air through the fireplace it can heat efficiently without the liner and a fully closed box. The model is a Wilkening.

Can anyone comment on this design compared to typical ones with the enclosed firebox and a liner up the chimney?

The model without the liner is considerably less expensive since the installation fees and liner costs are not there.

Any advice would be appreciated.

 

[Mike Wilson]

I don't know about Wilkening, but they look more like fireplaces and less like true inserts. Actually, they look like a glorified version of the little wood rack with the fan that fits in your fireplace and blows hot air back into the room... except with an air tight frame around it. In fact, it probably doesn't qualify as an "insert," and that's why legally there's no requirement for a chimney liner, block off plate, etc. Its a nice set of almost air-tight doors with a heat exchanger built into it. I'd love to see some efficiency, burn time, and GPH pollution numbers on them... it would certainly help.

Regarding liners, in brief, I have had my insert set up both ways, one year without a liner, one year with a liner. I would never, ever, ever ever ever consider operating an insert without a liner, ever again. The performance difference was night and day. Burned less wood, made hotter, longer, more consistent fires, less creosote, and an overall better experience with the liner. Do not even consider not having one. My dealer installed mine without it, said I didn't need it, etc... BS. Get the liner, and don't let anyone tell you otherwise.

-- Mike

 

[botbotfling]

Does the use of a liner reduce or eliminate the existence of creosote? Is a chimney cleaning still necessary when you have a liner?

If I am about to purchase an insert with a liner, how important is it to get the chimney inspected and cleaned prior to the installation of the insert and liner? Am I throwing my money away since the exhaust will go through the liner and never tough the masonry chimney?

 

[elkimmeg]

All liner manufactures by law as part of their listing require the chimney to be cleaned and inspected prior to installing a liner
the chimney must meet NFPA 211 Standards to be used with wood stove insert
NFPA code And the International Mechanical code also require the flue to be cleaned and inspected any any defects address prior to installing any stove and or liner Further comment on liner requirement I will review the manual of the stove you are considering

Page 2 of your manual also states the need to inspect and clean the chimney this is not an insert but a firplace placed into a masonry fireplace It says it is high efficiency yet thee is no EPA listing or UL listing Also recommended is a top chimney damper when not in use You would be hard pressed to have any inspections office grant a permit for an appliance not labeled or listed

What is high efficiency without proof?

 

[BrotherBart]

Even if there were no codes you should get the creosote out of a chimney before putting a liner in. The liner can get hot enough to ignite latent creosote on the chimney walls and at that point you have a very hot fire in a sealed space if you have a proper top plate and lower block-off plate installed. If you are lucky the fire will exhaust the available air and go out. If not all hell will break loose in that chimney.

BB - Who intentionally set off a chimney fire to clear the way before installing one of his liners. This was done by a professional maniac. Do not try this at home.

 

[Gooserider]

Does the use of a liner reduce or eliminate the existence of creosote? Is a chimney cleaning still necessary when you have a liner?

If I am about to purchase an insert with a liner, how important is it to get the chimney inspected and cleaned prior to the installation of the insert and liner? Am I throwing my money away since the exhaust will go through the liner and never tough the masonry chimney?

A liner will probably reduce the amount of creosote you get, especially if you use an insulated liner, but it will NOT totally eliminate it. You will still need to clean the chimney, but having a liner makes it a much easier process, you have in essence one continuous, constant diameter tube from the insert to the top of the chimney, so it is a simple matter of running the brush up and down a couple times and you're done. If you are running a modern EPA approved stove or insert, most folks do this no more than once or maybe twice a year. Usually you will need to do some prep work to get the insert ready for cleaning, but generally you don't need to remove or disconnect it - just prepare it by removing baffles or burn tubes that might be in the way, brush the crud into the insert, and vaccum it out... Some you can even clean from the bottom and not have to go on the roof at all.

W/o a liner, you typically need to disconnect the insert, remove it, remove the direct connect pipe and blockoff plate, brush the chimney, clean the smoke shelf and other chimney parts, then put everything back together - LOTS more work!

In terms of cleaning the existing chimney, yes, it's required that you do so as Elk has already stated. (What he didn't mention is that if there are problems with the existing chimney, using an INSULATED liner can solve many of them and get you up to code requirements w/o major problems.)

Gooserider