Advice/Help pellet stove install

Been searching forums and googling my life away for about a week and still can't find a resolution so thought I would post to the community and see if anyone can help/advise.

I was just gifted with a new us stove 5660 pellet stove. We currently have a vermont castings aspen which is fine but we are anxious to install the new toy and keep the woodstove as a backup... this is key. We currently have an existing brick and mortar chimney in the center of our house with snap lock pipe to the thimble and from there it has a 6" clay liner that is a 9' vertical rise from the thimble... according to the manufacturer this is fine for venting purposes and does not need a liner. I am just not having any luck finding an adapter to go from the double wall 3" pellet pipe to the existing 6" snap lock type thimble and I dont know where else to look. Yes I could line the chimney but I dont really want to do this because I intend to keep the woodstove and a cord of dry wood handy in the event we should require heat with no electricity aval. IE move the pellet stove and reconnect the aspen should the need arise. Duravent makes the 3 to 6" adapter but it is for double walled pipe on the 6" end so that is not going to work unless there is something to go from the snap lock to double walled side of the adapter(http://www.homedepot.com/p/DuraVent...let-Vent-Chimney-Pipe-Adapter-3074/100679686#).

Am I trying to do the impossible here or is there some secret society that only gives access to the required adapter if you know where to look for it...

Thanks for any advice/help

First thank you for the suggestion. The non crimped end of a 6" snap lock pipe will somewhat loosely slide inside the 3-6" adapter but the intent of the adapter is to hook up to double wall pipe on that end. I thought about doing as you have suggested and have dry fit it but doing so would require that I permanently seal that joint somehow because it is not designed to hook up to single wall pipe and I am reversing the connection right at the thimble (the single piece of snaplock coming out of the thimble would be going inside the adapter) think of someone reducing pipe size in the middle of a run and instead of getting the correct adapter they find a minutely smaller pipe and slide it inside the preceding one with sealant and then continue on(I suppose this can be made to function but it just wouldnt be the proper way to do it). There must be an adapter out there somewhere for this - I will try to call Duravent today and see what they can suggest, and/or if they start laughing and hang up on me

Well I probably didn't call it by the proper name but a metal sleeved thimble that snap lock pipe fits into. - I have nothing sticking out of my hearth. Anyways I contacted Duravent and the guy new exactly what I was trying to do and said I need a duravent 8675 adapter which I ordered and that should do the trick. Seems like this would be a commonly done application and I just could not locate any kind of illustration showing the needed adapter or detailed guide for making this connection. I guess the majority of pellet stove users who line their chimney have a full house automatic generator or some kind of battery backup with their pellet stove... otherwise I dont understand why there is seemingly so little guidance readily avail for this type of retro fit.

Thank you all for reviewing and your replies
- Larry

Here is the first review 6 hours or so after install. The 5660 puts out awesome heat - the noise level from the circulation blower is about equivalent to a box fan on medium but is tolerable and normal conversation levels are unchanged for the most part- I have the stove in my living room where the TV is and it is equivalent to having the window unit AC in there on low. I can definitely see where the low drone may bother some and being a tinkerer I will probably work to find a better blower... but all considered I am pleased with the unit. The original post was about the exhaust vent connections so on to that - I ended up using a slip pipe to go between the http://www.homedepot.com/p/DuraVent...let-Vent-Chimney-Pipe-Adapter-3074/100679686# and the thimble because the "required" adapter was not available locally and the shipping from everyone I could find was 7 days to ship plus the shipping time( I ordered it once and two days later the warehouse decided to let me know it would be 6 more days till it shipped... order canceled. The Duravent-pipe is good stuff(some high heat silicone on the stove adapter and thimble ensured no leaks) I have heat taped most of the other connections and the Dura-Vent Pipe is performing flawlessly. It is clearly not a Harman but its a very attractive unit and seems to work very well. I will post another update in two weeks or so. So far I am very happy with the purchase.

Thought I would stop back by and post a follow up. I have had no issues at all with the 5660.... everything working flawlessly so far and I would buy the stove again knowing the performance of it firsthand.

As asked to do I am stopping back to give a final review for the season as it is drawing to a close. I have no complaints about the US stove 5660, and in fact for the price would recommend and would buy it again - I have had zero issues with the stove. Feed it, light it, burn it, clean it according to the directions and keep your noodle warm.