Hi –

As many people have asked this question – I understand that undersizing flues greatly impact the performance of a stove. I saw a similar question on here from a member about undersizing from 7″ down to 5″ – which is substantial.

My question, however, is if an undersize from the 6″ recommended to a 5.5″ liner would see a drastic impact. We’re working with a 25′ chimney stack and a few bends which have prohibited the 6″ pipe from being installed.

For reference – I’m installing the liner to a Jotul Oslo wood burning stove using a heavy-duty flex liner.

Any thoughts or advice is very much appreciated.

Thanks!