1. Get it cleaned: You should be getting an annual physical from your doc and your chimney should be getting an annual checkup from a chimney sweep. The sweep will make sure the masonry, flue liner and venting system are clean and clear.
2. Test it out: Use a flashlight to check the damper, making sure it opens and closes correctly. Also check the grate, to make sure it isn’t sagging or broken, and the screen, which should be replaced if it’s ripped or doesn’t close properly.
3. Be picky about wood: Always try to burn dry, split hardwood, which leaves less creosote in the flue. Buy or cut your wood in late winter, before the spring sap hits, and let it dry outside for six months.
4. Warm the flue: Cold air in the flue will keep the smoke from rising up out of the chimney so, after you’ve opened the damper, encourage smoke to travel up by lighting a rolled-up piece of newspaper and holding it near the opening of the flue.
5. Easy on the firebox: More than three logs at a time may be too many and you risk the chance of fire escaping from the fireplace. This could be a bigger issue with older fireplaces, so be sure to get them inspected.
6. What not to burn: Painted or treated lumber and newspaper printed in color could release preservatives and inks that create noxious fumes. Also avoid burning pizza boxes, Christmas trees, driftwood and the burning of manufactured wood along with real wood, which could cause flare-ups.