Hi, new to the forum here. We have a Majestic MBU36 Factory Built Fireplace that was put in our home when it was built in 1985. We had decorative gas logs installed and stopped using them 2 years ago because of the continual problem with black soot in the house. Based on the recommendation of the propane company, we bought vent free logs yesterday and then called someone about having the fireplace cleaned before the new logs are installed. We were told we cannot have vent free logs in this type of fireplace at all. The place who sold us our logs knew it was an older home but not the type of fireplace, but has been in business for 25 years selling logs. Please tell me if we can use vent free or not if the flue is sealed off. Thanks!