BustaPimms

Not sure of exact size but a purely brick chimney and flue from a house built sometime around 1930 in rural Scotland.

Thanks for the advice. Much appreciated and that's what I'm going to do then I think.

Hello all, I would appreciate some advice regarding my multifuel burner that I'm about to have installed. I have recently bought this stove https://www.gr8fires.co.uk/arada-hamlet-solution-5-widescreen-ecodesign-ready-multi-fuel-wood-burning-stove-10080 to install at my house along with this cowl https://www.gr8fires.co.uk/pot-hanging-chimney-cowl-for-5-inch-flexible-flue# from Gr8Fires.co.uk . They were out of stock of flue liners so I ordered this flue liner from Stovebay https://www.stovebay.com/6m-flexible-flue-liner-316-316-150mm.html As you can see, I have ordered a stove with a 5 inch flue outlet and a 5 inch cowl, and then accidentally ordered a 6 inch flexible flue liner. Because I was away when these items were delivered I can now not return them it as it's past the 14 days return period. I know I can get an adapter for the stove top to change from 5 inch to 6 inch but does such a thing exist to adapt a 6 inch flue to a 5 inch cowl at the top and is that even advisable? Any suggestions much appreciated