During the cold months, you'll get a lot of use out of your fireplace. Since it's used so much, you want to perform maintenance on it to make sure it's not a hazard in your home.
Cold Season Maintenance
You can start by removing the ashes from the fireplace. During the cold season, make sure that the ashes don't build up to a depth greater than about two inches. Once the cold season is over, you may want to remove all the ashes. Use a flat fireplace-shovel to clean out the ashes. Place them in a bucket for easy removal and disposal. Remove any remaining ashes or other dry debris using a shop-vacuum with a filter bag.
Tip: You can add fireplace ashes to your compost pile.
Getting soot and fire-stains out of the firebox takes a little more effort. Make a soap and water mixture, and spray that mixture on the stains. Use it liberally and let the solution stay on the surface for about a half hour. This will soften the stain. Then, grab a stiff wire brush and scrub the surface.
For stubborn stains, you may need to use something stronger than soap and water. Muriatic acid is an abrasive chemical used to clean fireplaces.
Safety Tip: Muriatic acid is a harsh chemical, and is also toxic. Wear eye protection, protective gloves and clothing, and follow all safety precautions printed on the bottle.
Only mix one part muriatic acid with 10 parts water, and apply the solution to the brick or stone surfaces of the fireplace. Like the soap/water solution, you should allow the acid to soak on the surface for about 30 minutes before using the wire brush.
Also, use the metal brush to scrub off rust and debris from the damper. You'll want to wear old clothes, eye protection and gloves for this job. The damper is usually quite dirty and difficult to access. Check that the damper mechanism is working correctly so the damper can open and close freely.
Warmer Season Maintenance
Typically, you want to hire professionals to peform outdoor maintenance on your chimney. However, you perform a few tasks to make sure the chimney is safe.
Check the chimney cap's condition. You don't want it to be clogged and sometimes leaves and other debris can lodge in the cap.
A wire screen will keep debris and animals from getting down into the chimney. If you don't use your fireplace regularly, you may find animals trying to make a home in your chimney.
You can also examine the mortar between the bricks. Make sure there's no cracking or flaking. Also, check the flashing (where the chimney meets the roof). There needs to be a watertight seal. If it's damaged or cracked, you can patch it with caulk.
If you use your fireplace frequently, you should hire a chimney sweep at least once a year. It will ensure that your chimney doesn't have an unsafe build-up of debris. That debris is a serious fire hazard.