@Frustrated8
Personally I wouldn't recommend putting a TV of any kind, be it Sky Glass or otherwise, anywhere near a mulit-fuel burner.
Every house and every heating installation is different though. It may be that your chimney breast, presumably with the flue going up behind it, is superbly insulated and will not heat up excessively, but I still wouldn't like a major heat source pumping out hot air right underneath my TV.
Sky Glass, being a one-box solution for video and audio, has the sound bar and all speakers built-in. If any single component gets too hot and malfunctions then the entire TV is out of action. It's not a simple case of just swapping a speaker or replacing a WiFi antenna.
I think the best advice would be to wait until you have moved in to the property and fully test how hot the chimney breast and the area immediately in front of it gets. Check how much hot air rises from the front of the burner as this would potentially be rising straight up into the soundbar on your Glass TV. You wouldn't want any of the glue securing the speakers to the inside of the soundbar to melt.
