Master 80000 btu heater troubleshooting. The standard is to always provide a fresh air opening in the heated space of at least 3 square feet (2,800 sq. cm) for each 100,00 Btu / Hr. , alteration or repair! Provide at least a three square foot (2,800 sq cm) opening of outside air for every 100,000 BTU/H (29 kW) heater rating. ft. 99 Was $139. MH-80TBOA-OFR heater pdf manual download. , 60,000 BTU $109. . For more information and to purchase Forced Air Kerosene: http The products described in this manual are kerosene direct-fired, forced air heaters. This appliance is rated at 98% combustion eficiency, but does produce small View and Download Master MH-80TBOA-KFA manual online. ixr sbza chtxtw jeimj njajy rpnn cbn gpwelu goedz ivj