Lyemance Chimney Damper application Q

Bob Harper_2

Not a ringing endorsement that he has been there so many times and never called this out. Maybe you should switch to a Certified Fireplace Inspector:
www.f-i-r-e-service.com

Unlike CSIA Certified Sweeps, FIRE Service Certified Fireplace Inspectors receive 6 days of intensive hands on training and class room work with homework. CSIA means you passed a multiple choice test.

So, how does he sweep your system? Pull the stove and liner, sweep the chimney, sweep the liner, then reinstall the whole mess?

Check in NFPA 211 and the liner listing.
HTH

CC.Rob_2

question

From past discussions, I understand that a few people here have the Lyemance Chimney Damper. Need some opinions and feedback, please. I'm thinking of having one installed on my fireplace chimney flue (12x12 clay tile) to hopefully eliminate the water that runs down the chimney when it's rainy and windy (wind blows rain under the existing cap).

The fireplace has a (Federal Airtight) woodstove with a ~6 ft section of oval SS liner going up through the damper plate to a couple feet past the smoke shelf (it's a nice install -- has a bottom cleanout section, supports for the top of the liner, etc.). The cable/chain for the Lyemance damper would be passed through a hole to be drilled in the damper plate and terminated in the usual fashion for a standard fireplace.

The installation would be done by a CSAI sweep who's maintained the chimney for the past 7 years. His only reservation (and he's querying Lyemance/Homesaver about it), is the potential for smoke filling the house should someone forget to open the damper. How this is any different than a fireplace application, neither he nor I can say.

Any thoughts would be appreciated.

Thanks.

Brad White_9

We love ours

but it is used in a conventional fireplace. As you may know, the S.S. operating chain/cable runs down the chimney itself.

In your case, I am not sure how it would cleanly serve the function if it has to pass through the septum plate (damper plate) where the wood stove smoke pipe penetrates that. That becomes another potential snag if the cable and bracket do not align just right. A wear point too, unless you make the opening larger and if you do that, does it compromise the air tight qualities? Just a thought.

There is a bracket mounted on the side of the firebox through which the cable passes. When closed, you pull down and latch a chain link into the keyhole slot. Release and the handle stops at the bracket if you can picture that. Logistically, you would have to ask yourself how that might work in your case.

Part of the operating appeal to the Lymance that we like is the "snugness" of the closure. When the pivot damper closes there is some "give" as the silicone seal is compressed. As you also may know, if the cable breaks it fails open. The cable tension holds it closed.

CC.Rob_2

your thoughts are mine

Thanks Brad. Thinking out loud here, if I may.

Figuring out where to make the hole in the damper/septum would require setting up the whole Lyemance assembly and seeing where the cable wants to "lay" as it were, when the Lyemance is open and closed. Is it a straight pull or does the angle of the cable change between damper open and closed? If this is a 1/2" hole (or anything less than say 1"), I don't foresee a problem, but if there's a changing angular component that requires an oval or large hole, then I'd likely have to rethink.

A hole in the septum could be lined with a wear-resistant plastic thimble, and/or potentially an RTV plug if airtightness is an issue. The cable would ride through that; wearing, yes. Probably needs some maintenance/rebuilding over time. Likely no big deal?

Other considerations. The wood stove is not heavily used. Maybe 15-30 days/season. So the primary function of the Lyemance is to reduce/eliminate the water problem for the 80-125 days/yr with measurable precip, and have the side benefit of improving (but for the cable penetration) the airtightness of the chimney and house. A somewhat secondary consideration is that eventually we'll have a hurricane or two here, and I'd really like to avoid having a lot of water come down the chimney when the rain is blowing sideways at 74+ mph and/or the cap is compromised. It's bad enough at 45-55 mph....

Brad White_9

I think you are on-track with your arrangement

The cable does follow a straight line as much as a change in lever-end from pivot point allows over the height of the chimney. Where the chain/cable end latches into the bracket, the lateral distance at that point is less than an inch I would guess, probably much less. The cable fits into a fixed keyhole shaped opening so passes through the eye then locks into the tail when closed. You can see how small a "play" that will give you.

We think alike re: grommets or RTV silicone at the wear point. You should still have good updraft but I would watch it the first few fires.

Agreed too that you should install it first to target your hole cutting. You like challenges.

Bob Harper_2

liiner cap

Your woodstove should have a stainless steel cap that mates to a full length listed liner. Woodstoves are not approved for top dampers, which can cause smoke spillage and CO. The Lyemance brand downsizes terra cotta flues already. To modify the liner would void the warranty and listing of the stove and liner. In addition, the Lyemance brand is known to act as a squirrel trap. Install the proper rain cap made by the liner mfr. If you have a non EPA Phase II stove and want to install a damper in the stove pipe to regulate the heat, that is allowed under NFPA 211 but not for EPA stoves. If your sweep performs a Level II inspection, I guarantee it will reveal you need a full length liner. Most stove mfrs require them now. A direct connect as you have is allowed ONLY if it passes the Level II. A 6" into a 12x12 is not allowed. You have a chimney fire machine right now.

CC.Rob_3

cap

Bob, Interesting info. Is the "not approved for woodstoves" an NFPA code?

The liner is only a short section that does not extend all the way to the top of the chimney, so there is no cap that matches.

We had a level 2 when we bought the house, and the sweep has been doing annual maintenance and inspections since then.

One alternative could be to line the whole thing and use the matching cap. Good thought, and probably better in the long run all around.

Thanks.