Just lucked on this thread, I didnt get notification of the tag, how does that work? Creosote comes from green wood. There are a few things to consider here. Does your flue have two or three skins/ layers? The hotter the inside of the flue operates in relation to outside of the flue the less creosote will build up. The creosote condenses out of the smoke like water out if air on a cold window. Three layer flues are now the legal requirement for all new fitments, it keeps the inner layer hotter and stops the house burning down when the flue catches fire. The creosote is best dealt with by having well seasoned wood. The next best way to deal with it is to split the wood smaller, this makes the fire burn hotter which burns more of the creosote out of the wood before before it goes up the chimney where it condenses out of the smoke. Of course the smaller you have the wood the more often you need to add wood to the fire but you need to avoid creosote build up at all costs as it will eventually catch fire in the chimney and in the old days with one layer chimneys, the next thing that would happen is that the house would burn down.... With the smaller wood you will be able to have a smaller fire to get the same amount of heat out of it so it is actually a more efficient way to run your fire as well. Running smaller wood will also stop you from putting too much wood into the firebox at any one time. A lot of people run the firebox overloaded with wood and the fire cant get enough air in relation to the amount of wood that is in it. ie it runs too rich like a car with the choke on in the old days. This obviously exacerbates the creosote issue. See if you can find some well seasoned hard wood to mix with the greener stuff. Your wood supplier might have some if you explain to him what is happening. Hope this helps.
