Glass fireplace doors are a popular option for fireplaces of all kinds, including masonry fireplaces and prefabricated fireplaces. Wood burning fireplace inserts and wood burning stoves have doors with glass windows in them. Direct-vent gas fireplaces and direct-vent gas inserts have solid glass fronts. These doors and fronts use a special, heavy-duty glass which is designed to withstand the repeated heating and cooling experienced by a fireplace as it is used.
On the outside of the glass (facing the room), fingerprints and dust can build up as on any other window. On the inside of the glass (facing the inside of the firebox), byproducts of combustion (such as soot and other chemicals), or the residue from condensation (water in the air collecting on the glass when the temperature inside the fireplace differs from the temperature in the room) can accumulate. These substances can block your view of the fire, damage the glass, and can sometimes be combustible. Typically, fireplace glass doors or fronts need to be cleaned once a year, but heavily used fireplaces may need to be cleaned more often.
To clean your traditional fireplace’s decorative glass doors, your wood burning stove or insert’s glass window, or your direct vent gas fireplace’s glass front:
- The fireplace should be allowed to cool down completely before cleaning. Gas fireplaces and appliances should not be cleaned while they are running.
- Be sure to wear gloves and/or eye protection, depending on the cleaner you are using (check the instructions).
- Keep children and pets a safe distance from your work area.
- Check the instructions for your prefabricated fireplace or gas appliance to be sure the cleaner you plan to use is appropriate for the appliance. Using the wrong cleaner can void your warranty!
- Do not use abrasive cleaners or scrub pads, which can damage the glass. There are special products available specifically designed to clean fireplace glass.
- You may need to remove the metal surround of the fireplace to get at the glass front, especially in a direct-vent gas appliance. The surround usually lifts off without tools. Your appliance manual or manufacturer web site can illustrate this process for you.
If you see black, sooty deposits on the glass of a gas-burning fireplace, insert, or appliance, this is an indicator that the gas burner in your fireplace is not functioning correctly, and is not completely burning the gas. Do not use the fireplace, and get it serviced right away.
If you see cracks in the glass, this means that the glass structure is weakening. This happens over time as the glass expands and contracts due to heating and cooling. If your prefabricated fireplace doors have cracks, get them replaced as soon as possible, as they may shatter if heated. If your direct-vent gas fireplace or insert has a cracked glass front, do not use the appliance, and be sure to get it serviced soon.
A grayish coating of ash on the inside of a wood stove or wood burning insert door is normal. Brush the glass clean (a plain paper towel or a dry paint brush will do) once a week or so to keep the caustic chemicals in the wood ash from permanently etching the glass.
If you replace the glass doors, window, or front on your fireplace, stove, or insert, be sure to use manufacturer-approved replacements. Improper replacement materials can void the warranty and cause severe damage to the appliance.