Mr. Heater F299720 Vent-Free Blue Flame Propane Heater, 20,000 BTU

(10 customer reviews)

Brand Mr. Heater
Color Multicolor
Power Source Gas Powered
Heating Method Convection
Heating Coverage 500 sq ft
  • 20,000 BTU Liquid Propane heater to heat spaces up to 700 square feet.
  • Blue flame burner for even convection heat. Run Time (Hrs at Max BTU)- 21.59. Fuel Consumption/Burn Rate (Gal/Hr)- .926 lbs/hr.
  • Automatic low oxygen shut-off system (ODS). CSA Certified.
  • Operating this heater at altitudes over 4,500 FT above sea level could cause pilot/ODS to shutdown the heater.
  • Theromostat, legs and wall mounting hardware included.

This Blue Flame 20,000 BTU Liquid Propane Vent Free heater is the perfect supplemental heating solution even on the coldest days. This heater is conveniently equipped with a thermostat for superior control of the temperature in your space. Also, with a battery powered electronic ignition, starting it is a breeze – battery included. This unit can be permanently mounted to the wall or securely fastened to the floor with included mounting brackets and fasteners. A clean burning blue flame tube burner uses the natural convection of the burn to circulate warm comfortable air. With a factory standard Oxygen Depletion Sensor (ODS), rest assured this heater will provide you with years of comfortable and safe heat.

Can be wall mounted or freestanding, feet and hardware are included.

Clean burning blue flame tube burner uses convection heating to warm the air.

Wire guard protects against contact with burner.

Please note when operating this heater at altitudes over 4,500 FT above sea level could cause pilot/ODS to shutdown the heater.

Weight 24.75 kg
Dimensions 20.25 × 9.25 × 25.25 cm

Mr. Heater




Gas Powered




500 sq ft


30000 British Thermal Units


20.25 x 9.25 x 25.25 inches, 20.25"D x 9.25"W x 25.25"H


24.75 Pounds, 24.8 pounds








April 1, 2016


Mr. Heater, Mr. Heater Corporation

10 reviews for Mr. Heater F299720 Vent-Free Blue Flame Propane Heater, 20,000 BTU

  1. Amazon Customer

    No worky above 4500 feet.
    When they say it won’t work above 4500′ they mean it and there are no adapters or jets available. My cabin is at 7000′. It works sometimes not always depending on weather. Before it goes out the pilot will kinda “putter putter putter” then go out. Otherwise (lower) works great except it’s a real gas sucker.

  2. Jennifer Hildreth

    This little heater warms out little cabin and looks great also. I highly recommend.

  3. clay alexander

    Clean burning and efficient
    This is a very good heater. I don’t understand why people would find fault in it.

  4. John S

    Billed as ventless but it still needs fresh air ventilation. Works Great.
    Safety first… It is important to note while the heater does not require a flu to exhaust combustion or waste gasses it does need fresh air in some manor. In a tightly closed indoor space one should open a window or otherwise provide to allow fresh air to enter the space. I would also recommend not using inside unless you have a CO (carbon monoxide) detector installed. (Despite the oxygen detector in the unit. …That said;The heater Works well and burns cleanly and quietly.The heater puts out a decent amount of heat, (I have added the blower kit) I am using it to warm a garage work shop and as supplemental heat to help get the items in the space up to temp, then turn it down. While using withside temps well below freezing the space warmed up fairly quickly in a well insulated garage with two walls below grade, I was able to hold the temperature using a lower setting once everything was warmed up. It’s size allows it to be easily stashed out of the way when not in use and only needs to be pulled out a few feet while it is turned on. It is clearly a well made product and I a sure will serve my needs for years.

  5. Stretch55

    A very good heater for my purpose
    I was very happy with the way the heater came. Package was fine. All the corners are protected by thick Styrofoam. Gas line that feeds this is from the underground propane tank so my pressure is constant. A 3/8 NPT by 3/8 flare elbow is all you need from the hardware store and the necessary trac pipe or appliance pipe.Lights easily and the thermostat works well, so far is maintaining 60° in my garage.

  6. Epoxyco

    This heater works very well along with the built-in thermostat
    If you need a portable heater that really works, this is your heater

  7. BD Close

    Awesome unit
    Love this heater

  8. Allen Spore

    Oxygen sensor too sensitive

  9. David H

    works at 6,800′
    We’ve been using this about a week now and these are my initial thoughts. We live in the AZ hi country and while it doesn’t get MN cold, it will get down close to zero. We are full time in a 40′ 5th wheel, moved here two years ago, and used a Big Buddy last year, which worked great. The obvious problem with the BB is the lack of a thermostat. I tried it first because of the many reports of loud noises in the blue flame style. We should have gotten this first. Apparently, there have been enough complaints about the cheap elbow that they don’t bother anymore. Mine didn’t come with one. I purchased a brass 3/8 male npt to 3/8 male flare 90 degree and a 3/8 female flare to 3/8 quick key release fitting to fit the female quick release on our gas line. That allows easy swapping to the BB if there’s a problem. Which there hasn’t been to this point. Since I had been using the line with the BB, there was no air to purge and it lit quickly. A few days playing with the thermostat gave a setting that keeps it about 70 degrees. The thermostat is NOT a timer, as some suggest, but a true thermostat, tho it is an indicator, not numbered in degrees. There have been tales of noises including banging, which I haven’t heard, and a whooshing when it lights. Sitting close to it, I can just hear it light if there are no other noises. This is NOT a recommendation, follow all the described safety rules, but we don’t leave a window or vent open anymore. Again, I DO NOT recommend this, I’m relating our experiences. We have two CO detectors, one a few feet from the heater, a propane detector in the room, and a Macaw living within a few feet of it. The Macaw has yet to show any ill effects. We have a big residential propane tank, so I can’t compare gas use between this heater and the BB, but both use significantly less propane than the factory heater. At this point, I would recommend this heater.

  10. Mary mcintire

    My friend seems to be very happy with his heater
    Was not difficult to install and keeps the space well heated

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