In the beginnig of the heating season tile stoves have to prepare in use after warm summer and autumn. There is a good point to ensure flue's accessibility for possible bird nests, leafs and possible humidity in the flue. When the flue is cleaned it's good to burn a little amount of wood with hot flame at first. Let this kind of "kynsituli" burn out without closing the registers. This is the way the flue is prepared to have a good draft of air for the upcoming normally usage.