The other day I started smelling smoke. Not near the pellet stove, but on the second floor. It took me a while to figure out what was going on. Over the past few years we have been improving the energy efficiency of our house, sealing leaks, insulating and finally this fall we replaced all of our windows. Now when the oil burner runs, the house pressure drops below outside pressure. Coincidentally the top of the chase the stove's flue runs through developed a leak. Now whenever the boiler is running and the stove is running (OAK) smoke is sucked into the chase and through the access hatch on the second floor. I placed a CO detector in the room with the hatch and it's sitting at zero. There are several causes of negative pressure in the house. These include; bathroom exhaust fans, kitchen exhaust fan, oil burner, and clothes dryer. I know that I have to fix the chase, I have already hired somebody to do that (I don't to work on the roof anymore). My question is, how do I balance the house's pressure so that air infiltration isn't as much of a problem? I just know that some wise-a$$ is going to tell me to open a window.