One of the most sought-after fireplace operation tips centers around what to do with your fireplace doors while burning – open or closed. This can depend on the type of glass being used. Understanding the different types of glass will help you with your decision. Fireplace doors are designed with certain types of glass, and that’s what dictates the best ways to operate your fireplace. The two main types of glass are built with either tempered or ceramic. You’ll want to know the type of glass your fireplace doors are built with before deciding if your doors can be open or closed while burning. Tempered glass doors are required on all prefabricated fireplaces,  and fire codes dictate they come equipped with this specific type of glass doors. Tempered glass is easily broken if there is prolonged exposure to high temperatures, like those coming from a fire in a fireplace. That’s why you should always keep your tempered glass fireplace glass doors open while burning. They can be all the way open or partly open depending on the draft they create. Ceramic glass fireplace doors are capable of withstanding extremely high temperatures. Ceramic glass is used for masonry fireplace doors and custom glass fireplace doors. It’s a code violation to use ceramic glass on prefabricated fireplace glass doors. If you have ceramic glass for your wood-burning fireplace glass doors, then you have the option of leaving your doors open or closed while burning. Your fireplace glass doors are more than a decorative accessory, and there are many benefits of understanding when to keep them open or closed including saving money on heating, enjoying longer burning, and safer burning fires. The decision to keep your fireplace doors open or closed has a direct impact on the costs of heating and cooling your home. For example, if in the winter you have an open fireplace flue and no fire burning, valuable heat is escaping out of your chimney. But if you have a damper as most wood-burning fireplaces do you can shut the damper and leave the doors open. Although you can close the doors to hide a mess, it helps block the smell of remaining ash and wood from burning the night before. However, you’ll want to monitor your open fireplace doors as having them too far open can suffocate your fire. Feeding your fire too much oxygen can suffocate the flames, resulting in a dull burning fire. So some adjustments will be necessary. One of the most important things to keep in mind when burning in a wood fireplace with glass doors is the general safety of your home and loved ones. Be aware of the fire in a fireplace and never leave it unattended when the flames are in full dance mode. If you’re unsure about the type of glass your fireplace glass doors are made of, then it’s smart to keep them open while burning until you’re certain. The last thing you want is to have to replace expensive pieces of glass for your fireplace doors because you weren’t sure if they could be closed. 

Snuggling up next to the fire with the fireplace doors open
Example of a chimney without fireplace doors
Its cold out, its nice to sit by the warm fire with open fireplace and bask in the heat
If you’re like a lot of people, you might put your fire out for the night and head off to bed, leaving your fireplace glass doors open. Although this is a common practice for many fireplace owners, it’s not the most energy-efficient move and you’ll want to ensure your fireplace glass doors are closed when there’s no fire in the fireplace.  Leaving your wood-burning or gas fireplace glass doors open along with an open fireplace flue in the winter will suck the warm air right out of your home. Closing your fireplace doors will not help a fire burn longer. If you’re looking for long, healthy burning fires, then you’ll want to keep your wood-burning fireplace glass doors open while burning. It’s common to convert your wood-burning fireplace to use gas logs. Gas offers many different benefits and is a great option for many homeowners. When burning gas logs in a wood fireplace, you’ll want to keep your doors open. Similar to wood, gas logs need oxygen to burn efficiently, so keeping your fireplace doors open will help the flow of oxygen to your gas fires. Make sure your fireplace is inspected and cleaned regularly, a dirty fireplace can affect the performance of your fireplace


Originally Posted At: To Close My Fireplace Doors or Not to Close Them, that is The Question! | Sootmaster Chimney Sweep