Gas Logs

Vented gas logs require a fully functional chimney to vent combustion byproducts outside, and they produce the most realistic-looking flames — but because the flue must stay open, most of the heat escapes up the chimney, making them primarily decorative. Ventless (vent-free) gas logs don't require a chimney, keep all the heat in the room, and are the better choice if supplemental heating is your main goal. Your decision ultimately comes down to whether you prioritize aesthetics or heating efficiency.

In most cases, yes — you can install either a vented or ventless gas log set in a fully functioning wood-burning fireplace, but there are exceptions, such as high-efficiency wood-burning units that are not compatible. You'll need a licensed gas professional to install the gas line and connect the log set, and you should always verify the installation requirements in your specific log set's owner's manual. A qualified expert can also help you determine whether vented, ventless, or a direct-vent unit is the best fit for your home.

To size your gas logs correctly, measure the width, depth, and height of your fireplace opening, and make sure the logs don't extend beyond the opening or block the damper. You should have at least 2 inches of clearance between the logs and the fireplace walls, and at least 3 inches between the logs and the burner system. If the logs are the wrong size, your firebox and gas valves can overheat, potentially causing permanent damage to your log set, fireplace, or home.

Ventless gas logs are considered a safe option when properly installed — they go through rigorous testing and safety approval processes, and include an oxygen depletion sensor that acts as a failsafe to ensure room oxygen levels always remain safe. However, most manufacturers recommend running them no more than six hours per day, and they should always be installed by a trained professional. Note that ventless gas logs are not legal in some states (such as California, Wisconsin, and Montana) and certain cities, so always check your local building codes before purchasing.

It's essential to have a licensed hearth professional inspect your fireplace, log set, and burner system annually, checking all valves, pipes, and gas connections. For ventless sets, clean the ember bed and logs every few weeks to remove soot buildup; for vented sets, have the chimney inspected and swept once a year and clean the logs thoroughly every few weeks — especially if you use liquid propane. Concrete or ceramic-blend logs can be gently scrubbed with a soapy solution and soft brush, while lightweight ceramic-fiber logs should only be vacuumed with a soft-bristle attachment, as water can damage them.