Unvented gas logs, can I keep a Chimney Balloon in?

Unvented gas logs, can I keep a Chimney Balloon in?

Jason – I converted my masonry fireplace with natural gas and installed an unvented gas log set. Can I install a Chimney Balloon above the damper, keeping the damper closed and ignite my gas logs without incurring any damage to the Chimney Balloon? The gas log set is rated at 39K but. Thanks, CB

Dear CB, If the temperature in the flue gets to about 200 degrees Fahrenheit it will trigger the release mechanism in the Chimney Balloon. Essentially the Chimney Balloon membrane melts and shrinks at the same time and the Chimney Balloon falls out of the Chimney. I’m betting that you will get heat conducting through your damper that will exceed 170 degrees within minutes with this vent free gas log turned on. Unfortunately, the metal from the damper will conduct the heat right through.

On the other hand, it will benefit you to use a Chimney Balloon above the damper when you are not using the fireplace. This is how it is normally used and it will keep your nice warm inside air inside where it belongs and not be floating up past a leaky damper.

How to plug a round 8″ flue pipe with a swivel damper?

How to plug a round 8″ flue pipe with a swivel damper?

Q: Hi Jason, Here are a few pictures of my fireplace damper and round flue pipe. The diameter is 8″ in the flue pipe. What size Chimney Balloon do you suggest? – LG

A: Hi LG, This application is one of the most common styles of damper and flue that we run into. These pre-fabricated fireplaces are very common, but the butterfly damper that you have there is notoriously leaky. The great news is yours looks like it has never been used, so you will have no soot to deal with when you install a 9×9 Chimney Balloon. Take the deflated Chimney balloon and slide it in past the open damper. Put a couple of puffs of air into it and make sure it is installing nice and horizontal. Then inflate it the rest of the way until it tightens up, and close the valve. The 9×9 install is very easy to do. – Jason