Woodstove Trouble. At our wit's end!

Hi People,

I have been having an issue with my woodstove/wood furnace all year and have been having a hard time figuring out what to do. I have asked numerous people and have been given many suggestions, but none have worked. Hopefully someone here might be able to help. Here is my setup. Bought a house last year that has a US Stove hotblast forced air wood stove. Stove worked great last year. Almost kept the house too warm. This year I began using it again, but every few days I get smoke puffing back into the house a couple hours after filling it. It is a pain during the day, but even worse when we are sleeping. To correct the problem, I spin the bottom dial out, which allows the fire to almost run away. Stove pipe temp goes from 250 degrees to 400 degrees in a matter of minutes. When I try to slow it down by spinning the dial back in, I have to do it extremely slow or it starts puffing in the house again. I have a 6" outlet on the stove, which is connected to a 6" stove pipe which runs up and then out the wall to an 8 inch double wall stainless chimney pipe. I have verified that the chimney height is high enough and have even changed my cap to a special wind resistant type cap. I am burning wood that was cut and split in October of 2008. I clean my pipe every weekend and have not had any build up as of yet. It also seems to do it if there is a good bed of coals in it and I load it with wood. I cannot figure out what has changed between this year and last. I don't seem to be doing any thing different. My wife and I are about to our wits end with the stove and are expecting our first kid any day now. We are getting tired of waking up to a smokey, smelly house at 2 o'clock a.m. If I can't fix it soon, I am shutting it down, which is a shame because it works so well. Firebox is usually about 340 to 360 degrees and stove pipe is around 300. Does it whether the wind is blowing or it is calm. Any help would be greatly appreciated. If you need more info or have question please let me know. Thanks

Wow. I appreciate the quick replys. Let me see if I can answer the questions from the posters.

Poster 1. Wood is Maple, Oak, Beech, Ash mix. Dryer & Stove are on main level, but we are not running either one when this happens at night. Cap is checked weekly and it was doing it before the new cap was installed. The new cap was installed becuase someone thought that would fix it. Stove is cleaned when chimney and stove pipe are.

Poster 2. I am not sure of the effects of negitive pressure, but this has been tossed around before. There are many different openings between the upstairs and basement. The basement is not sealed off or closed off from the upstairs. The furnace part blows the hot air upstairs and the cold air is returned through vents in the floor of all rooms and there is no door on the basement stairs going down. Not sure if this helps describe the set up. But it didn't do it last year, thats the confusing part. I usually open the basement sliding glass door to help air out the house and that won't stop it.

Poster 3. I clean my flue usually one a week becaue I do it everyday after it has puffed in the house just to make sure that there is no restriction. I am afraid that the one time I don't check it, there will be one and it will cause a bigger problem. There is no buildup. Not too sure about temps, but my thermometer says to keep the flue temp between 240 and 450. I would be afraid that if the stove was that warm then the flue temp would be to high. I could be wrong though. I am also afraid that if I kept it that warm I would be filling it every 4 hours.

Poster 4. I too was told that the wind was probably the cause. That is why I swapped caps. But I have also noticed that it does it just as much when there is not wind at all. Hahaha. I agree that when the temp is high my wife complains that its too hot in the house too.

Poster 5. No major changes it the house. I check the cap weekly. Never looked into an inline stovepipe draft inducer. I'll have to follow that lead and see where it goes. Thanks for the tip.

Gee guys, again, I really appreciate the questions/help. Let me know if you need anything else.