Hearthrite - Blue Flame Wall Mount Heater - 20K BTU | Foster Fuels Home Products Hearthrite – Blue Flame Wall Mount Heater – 20K BTU Hearthrite – Blue Flame Wall Mount Heater – 20K BTU Brand: Empire Weight: 30 lbs Product Number: 933031003 Price: $279.00 Add to cart Product Description: No matter what type of space you need to heat, Empire’s American-made zone heaters will suit your needs perfectly. Empire Vent-Free Heaters are 99.9% fuel efficient. Because they don’t require outside venting, no heat is lost. And best of all, Empire Vent-Free units do not require electricity to operate. Our Blue-Flame heaters work by heating the air, which then surrounds people and objects with “atmospheric” warmth. Warranty Information Manufacturer warranty is not valid unless installed by a Foster Fuels technician.