Osburn 1800 woodstove...liner reducer from 6" to 5" safe?

[lovemyfire]

I'm new to this hearth forum, so please be patient with me!

So I have a gently used Osburn 1800 wood stove insert that I purchased recently. Overall, stove has had little use and I got a good deal on it. It came with the 6" x 25' Duravent Flex stainless steel liner.
This is my issue: My chimney flue only opens to just slightly over 5 inches, so I can only get a 5" liner in the chimney. The hole in the top of the stove that takes the liner is 6 inches.
This is my question: Can I use a reducer which will start at 6" at the stove top and reduce to 5" that will fit into the flexible chimney liner? Do you think this would have adverse effects on the stove?
I called 2 fireplace/stove stores and neither one would give me a solid answer and I don't want to bust out the flue to make a bigger opening because I am only going to live in this house for about 4 years and then turn it in to a rental and I don't want renters messing with a wood stove so I want to be able to close the flue back up once I take the stove out.
Your comments are appreciated. Thanks!

 

[BrotherBart]

Is that a tile lined flue? Five inches sounds too small for use in an open fireplace. What are the exact inside dimensions of the flue?

 

[lovemyfire]

Is that a tile lined flue? Five inches sounds too small for use in an open fireplace. What are the exact inside dimensions of the flue?

I don't know. It is a masonry brick fireplace. The inside dimensions of the flue is just a hair over 5" wide and 24" long.
The house was built in the 1940's.

 

[BrotherBart]

I think you are looking at the damper in the fireplace smoke chamber. Not the actual chimney flue. Has anybody been up top to look down in the chimney?

 

[lovemyfire]

I think you are looking at the damper in the fireplace smoke chamber. Not the actual chimney flue. Has anybody been up top to look down in the chimney?

My apologies!! I see how I made that confusing.
Okay, the damper opens to 5"x24". And that is where our problem is. The chimney itself is plenty big for the 6" liner but the damper size won't allow us to put a 6" liner through it. That's why I wondered if I could use a 5" liner. So I would put a reducer from 6" (at the stove top) to 5" that would take the 5" liner (and even getting the 5" liner through the damper will be very close).

I was told that we could bust the damper out to make more room for the liner but once it is broken, that's it. And I really don't want to break it out because when I eventually take out the wood stove and liner, I can't close the damper.

 

[BrotherBart]

The correct move is to cut the damper frame just enough for the liner to fit through it. If you want to go back to a fireplace you put in a chimney top damper for a couple of hundred bucks. They are better dampers for a fireplace anyway.

http://www.woodlanddirect.com/Chimney/Top-Sealing-Chimney-Dampers/Lyemance-Damper-Energy-Saving

 

[Swedishchef]

It kind of sounds like BB knows what he is talking about. Pfft.
:D