If the glass on your wood stove or fireplace turns black quickly, there are several possible reasons. The most common ones are:
Poor-quality fuel
For optimal combustion, the moisture content of your wood should not exceed 15–20%. A simple test will help you quickly determine whether your wood is dry enough:
- Take a log
- On one of the cut ends (lengthwise), spread a small amount of dish soap or kitchen soap over a 5–6 cm diameter area.
- Blow into the log from the opposite side. If bubbles form on the side where you applied the dish soap, your wood is dry. If nothing happens, it isn’t dry enough. You can try leaving it indoors for 2–3 days before using it.
There isn’t enough airflow inside the stove
An outside air intake is necessary to ensure your stove operates properly. Modern wood stoves are designed to direct a stream of air toward the front of the glass to keep it as clean as possible. It’s important to have plenty of air when you light a fire. Air is essential for a clean and complete combustion process, during which the temperature is high enough to burn off the gases and particles emitted by the wood. If the gases and particles are not burned, soot will build up in the flue, or black smoke will emerge from it. That’s why you should check to see if the smoke coming out of the flue is white or clear when you light a fire in your wood stove.
Be sure to thoroughly clean the combustion chamber (ash grate) using a suitable brush or an ash vacuum and to empty the ash pan regularly so that the air intake isn’t blocked by residue.
Insufficient draft
The flue is essential for the stove to function properly. Keep in mind that even the best stove will not work perfectly if the draft is insufficient or incorrect (minimum flue height of 3.50 meters). Before the start of a new heating season, the chimney flue and the flue gas connection pipe must always be inspected to ensure they are not blocked. A chimney sweep must inspect both the flue and the stove at least once a year. If you have any doubts about the condition of the flue, you must contact a chimney sweep immediately.