Cold Air Under Gas Fireplace

From the outside there is a fresh air intake on the chimney and there is a metal chimney exiting the top of the old stucco chimney.

Cold air under gas fireplace.

After inspecting i realize that the reason this room is always colder than the rest of the house is because there is a ton of cold air coming in underneath the gas fireplace insert. When you close the flue you re essentially plugging the chimney with a metal flap. You will stop the cold drafty air in the winter and keep warm humid air from coming in during the summer months. The airflow in the control area under the insert doesn t seem to be part of the gas system.

I am the original owner of the house and looked through the manual. I can t find where it is coming from nor how to shut it off. We recently bought a 1996 house which has a majestic gas fireplace. Even the heat fan that kicks in is located above the insert not below and there is no cold draft coming from the fan.

The second person told me it was a normal part of the gas venting air flow. It seems that the gas insert s enclosure bottom must sit off of the bottom of the fireplace opening by about an inch. Use our flue cover to stop the outside air from coming in through the flue. If you have the damper closed but cold air still sweeps across the room it s very likely that your damper is worn cracked warped or generally degraded.

I ve noticed it when it s not in use especially at night but it seems inconsistent and not necessarily predictable by the temperature or audible wind. A damper is a metal flap in your chimney that blocks cold air from coming in and warm air from escaping. There is no trouble shooting suggestion for this problem.