EKO flue size

[easternbob]

The new EKO manual states that you need a 8" diameter flue. I have a EKO 25 and that seems really big. I'm thinking it would be easier to maintain a good draft and the necessary stack temps with a 6" pipe? I purchased a draft inducer along with my boiler and plan on installing that in addition. I realize I need to start out with a 8" tee off the back of the boiler but was thinking of transitioning to 6" above that.

What size flues are other people using and how is it working?
Thanks,
Bob

 

[stee6043]

You'll find that several people on this site are running 6" pipe on the 25's and 40's with good results. You may also notice that a Class A 6" T will fit right over your 8" outlet....quite convienent....except that running Class A chimney pipe indoors is kinda pricey and not necessary for code.

 

[Medman]

I haven't fired mine up yet but I am using a 7" flue/chimney because the pipe was already installed in my garage. Dave at Cazy Heat recommends using a 6" chimney, because you can slip the collar of a 6" insulated chimney section right over the 8" flue collar on the back of the EKO - he showed me this in the store and I was impressed with the simplicity of the setup. Unfortunately for me I could not use this solution.
I think that 6" is lots, especially with a draft inducer. I live in just about the worst possible place for downdraft and haven't had a problem with the 6" chimney on my PE stove using a venturi cap on the top. In normal operation the only part of that chimney that gets any crosote buildup is the cap itself.