I am often asked if it is possible to mount a TV above a fireplace. The short answer is yes. How close you can mount the TV to your fireplace depends on several factors. Some of those factors include how hot your fireplace gets, whether or not you have a mantel above it, and if you are going to recess your TV in the wall. Several companies offer additional features that allow you to mount your TV even closer. Majestic offers the SmartWall TV Kit on their Jade Linear Gas Fireplace. With that you are able to mount a TV only 12 inches above the fireplace with no need for a mantel.
The best place to find instructions on mounting a TV above your fireplace is the installation manual. Most manufacturers outline the safe distance requirements and mantel options in the installation manual. Another factor is how hot your TV can safely get. Many TV manufacturers outline safe operating temperatures for their TVs in their respective manuals. Always consult both your fireplace and TV manual for safest installation of a TV above your fireplace.