Would a damper help Hearthstones Cat Design?

[Dajolu]

I am going to be installing a Green Mountain 60 in my house hopefully with in this month. I am wondering If I should put a damper in or not. I will have roughly 20-25' of chimney length. I have read some posts on this forum talking about the poorly designed catalytic combustor location on the Hearthstones and am wondering if I put the damper right on top of the of the flue that maybe it would help? I am considering getting a Duravent Damper/Adapter for the flue connection.

 

[begreen]

Go to the dealer's showroom and measure the flue collar ID on the stove first before ordering,

It's unfortunate that DuraVent puts the damper into their adapter instead of a regular 6" section of DVL. The adapter is 5 5/8" on the stove end which leads to a sloppy fit on some stoves while a regular section of DVL fits the flue collar very well. I ran into this with our stove and had to purchase a section of 6" DVL, remove the damper from the adapter, and then put it into the 6" section.

Will the flue system be straight up or to a thimble and then up the chimney? There is a big difference between 20 ft and 25 ft of flue. If it's 20' I would not put in a damper. If it's 26' I'd consider it, but probably would try the stove without one first. Reports are that the stove likes a stronger draft, so it's worth trying it out first. If the flue system has a couple of 90º turns in it, then I wouldn't put one in unless it ended up being needed.

 

[Dajolu]

Go to the dealer's showroom and measure the flue collar ID on the stove first before ordering,

It's unfortunate that DuraVent puts the damper into their adapter instead of a regular 6" section of DVL. The adapter is 5 5/8" on the stove end which leads to a sloppy fit on some stoves while a regular section of DVL fits the flue collar very well. I ran into this with our stove and had to purchase a section of 6" DVL, remove the damper from the adapter, and then put it into the 6" section.

Will the flue system be straight up or to a thimble and then up the chimney? There is a big difference between 20 ft and 25 ft of flue. If it's 20' I would not put in a damper. If it's 26' I'd consider it, but probably would try the stove without one first. Reports are that the stove likes a stronger draft, so it's worth trying it out first. If the flue system has a couple of 90º turns in it, then I wouldn't put one in unless it ended up being needed.

Thanks for your reply, the pipe is going to have a couple of 45's then into thimble to a tee up a lined chimney. Yea I think I will try it without the damper for now. I all ready ordered and received the duravent adapter (w/o the damper) and some elbows to do some test fitting. The adapter is like you described, loose on the flue collar. I put a double wall 45 elbow on the flue collar to test the direct fit and it is very snug and does not go down on the collar very far. Maybe with a 6" double wall pipe section I will be able to gently tap the pipe down on the collar to get it to seat further/better.

 

[begreen]

Good plan. The 90º turn up the chimney will slow things down a little. If you can, return the DVL adapter. It's not needed.

 

[Pinesmoke]

I read someone here say new cats can be "spikey" at first. My Mansfield took off a couple of times early on and I was glad to have a damper.

It's smoothed out since then but was pretty handy to calm things down.

ETA you guys type faster than I do. My stack is straight in the center of the house. Yours is probably a bit more mellow than mine.

 

[Dajolu]

I read someone here say new cats can be "spikey" at first. My Mansfield took off a couple of times early on and I was glad to have a damper.

It's smoothed out since then but was pretty handy to calm things down.

ETA you guys type faster than I do. My stack is straight in the center of the house. Yours is probably a bit more mellow than mine.

Not to deviate the conversion to much but is there supposed to be a gasket material to wrap around the cats before installing them? The owners manual describes a wrap of sorts were the instructions that came with the stove basically say to just place the cats on their designated locations. Can you shed light on that for me?

 

[Pinesmoke]

Mine are not "gasketed"they weren't when I picked it up from the dealer. They are just sitting in their pocket.

 

[GM80NY]

I would check from above. I’ve got the gm80 and i have three sections of cat and they all are individually wrapped with gasket. Installed 3 years ago.

 

[Narsil487]

Mine also do not have gaskets.