For most homes, you should have your chimney inspected annually and cleaned as needed, but a common rule of thumb is:

• Wood-burning fireplaces or stoves should be cleaned every year if being used

• Heavy wood use: You may need cleaning more than once per year, especially if you burn a lot of unseasoned wood.

• Gas fireplaces: They produce little creosote, but the chimney or vent should still be inspected yearly for blockages, corrosion, or animal nests.

Signs your chimney may need cleaning sooner include:

• Smoke backing up into the room

• Strong smoky or tar-like odors

• Poor draft

• Visible black, flaky, or shiny deposits inside the flue

• Evidence of birds or other animals nesting in the chimney

The U.S. standard from the Chimney Safety Institute of America recommends an annual chimney inspection, even if you don't use the fireplace often.