Question: The house was built 15 years ago and the woodburning stove is a fairly large one that has two oxygen control mechanisms on the front door (screw like bolts with silver circular dials to control the flow of oxygen) - there is no flue. The pipe is about 24 ft in length from the stove up to the spark arrestor on the roof. The pipe is triple-walled and I had the chimney swept by a professional in the Fall. The wood I'm burning is red fir which is the best burning wood we can get here (I live in Idaho, near Boise)- we can't get hard wood. I've heard locally, that red fir is the best because it burns the hottest and prevents creosote from building as fast, since the hot temperature keeps it burned off. My problem is that creosote keeps building up very fast, both in the pipe (which I've had cleaned about 4 times this Winter, so far) and in the metal wiring that forms the spark arrestor atop the chimney pipe (this builds up even more frequently). My pipe gets clogged with creosote typically about once a month and I've had to clean it each month, as smoke just starts pluming into the house and I can't get any oxygen flow for the wood to start. Could a poor stove design cause poor burning and then creosote buildup like this? Have you ever heard of a similar situation. I've had so many problems, that I've switched over to electric baseboard heat, because it was getting too expensive to keep having the chimney sweeper come out to clean the pipe. Answer: This is a combination of poor stove design..and an older chimney. Here's the scoop. Your woodstove, being "pre-EPA", does not burn the wood completely. Large amounts of water vapor and unburned gases (smoke) are being created. This is then being cooled in your long chimney, and it then condenses in the pipe. In one sense, you are running a distillery instead of a woodstove! You can try a few things. First, read all the wood burning and starting tips at https://www.hearth.com/what/specific.html. Burn hot fires, plenty of air but less wood.... You might be able to install a catalytic converter "retrofit", which sits on the flue collar on top of the stove. This may give you more heat, and clean up the flue. Ask your local hearth dealers about these devices.