Dyna-Glo wall heaters are the ideal choice for safe, indoor supplemental heating. This state-of-the-art vent free technology does not require a flue or chimney. These heaters are great for use in your home, cabin, or garage. Since these heaters do not require electricity to operate, they make an excellent choice for everyday heating, and emergency situations when the power goes out. Using blue flame heating technology, heat is distributed similar to your central home heating system. This Blue Flame Wall Heater burns with 99.9% efficiency, and operates on Natural Gas only. Not for sale in California or Canada. Check your local regulations on installation restrictions and requirements. Professional installation recommended.Dyna-Glo BFSS30NGT-4N 30,000 BTU Natural Gas Blue Flame Vent Free Thermostatic Wall Heater Professional Installation Recommended Natural Gas Ready (Fuel conversion not permitted) Blue Flame Technology works by convecting heat to warm the air the same way as a central heating system 15,000-30,000 BTU’s/hr. adjustable heat output for up to 1,000 sq. ft. Thermostat control knob automatically maintains your ideal heat level No electricity required allows for reliable back-up heating in case of an emergency situation DEPENDABLE – Ideal for daily supplemental or emergency use, such as power outages.nbsp; ECONOMICAL – Cut heating bills by warming only occupied areas.nbsp; COMFORT �C Heater automatically adjusts to your desired temperature; just like your home thermostat.nbsp; SAFE – Built-in oxygen depletion sensor (ODS) immediately shuts down the heater if carbon monoxide or lack of oxygen is detected.nbsp; CONVENIENT �C One continuous press of the battery assisted igniter makes ignition quick effortless.nbsp; VERSATILE – Includes all necessary hardware bracket for wall mounting.nbsp; UPGRADEABLE – Separately sold optional base legs (WBL100) provide the alternative of floor mounting. Separately sold optional Wall Heater Fan (WHF100) distributes heat in a quiet, yet powerful way.