A Mr. Heater Will Keep You Warm When the Cold Winds Blow

As I write, the weatherman just announced that tonight's lows will be in single digits and right now it's nineteen degrees outside. At times like this, I feel stupid about putting my workshop out in the barn instead of in my basement. I've had poor to fair luck with heaters over the years - an expensive kerosene heater I inherited from Dad takes too long to warm up; an electric model left in our attic by the previous owners blows circuit breakers. The Ms - as she so often does - found a solution: a propane-powered Mr. Heater Portable Heater MH9B, sometimes called the Portable Buddy. Now I can work on my more time-consuming projects in relative comfort, even in the dead of winter.


A propane-powered heater? Yes, propane: this heater is designed to run on the same one-pound propane cylinders used to power camp stoves and lanterns. Cylinders mount on the side of the heater body, where they screw into a brass coupling. Optional connector hoses allow Mr. Heater to attach to a twenty-pound propane cylinder such as those used for gas grills.

Mr Heater has four valve settings: off, light, low, and high. Heater output is nominally 4000 BTU on low and 9000 BTU on high. On high, the heater raises my 12x10 workshop (eight-foot ceiling, insulated) from below freezing to a much more comfortable 60º-plus in about forty-five minutes, then readily maintains a comfy temperature on the low setting. Unlike a kerosene heater, this propane model is odor-free; unlike an electric heater, it's quiet and can be operated anywhere and during power outages. The heater is advertised as being useful for spaces of up to 200 square feet.

The body and handles of the Mr. Heater are molded of ABS plastic with grooves on the handle and the feet to improve grip. The heating element is a ceramic grid that's set in a porcelain-coated reflector to direct the heat forward. For safety, the heater has automatic shutoffs for tip-over and low oxygen. The element is set about three inches behind a heavy wire grid to keep combustible materials away. The grid does, however, get hot enough to burn when you touch it. I've tried the tip-over sensor - it works - but not the low-oxygen sensor system.

Mr. Heater does require some patience to start. Since the fuel line must be purged of air and filled with combustible gas, the selector knob must be held depressed in the "ignite" position for thirty seconds before attempting to light - there's a pushbutton ignitor that supplies the necessary spark. Even after lighting, the knob must be held depressed for up to one minute to make certain that the low-oxygen sensor is functioning, and the heater must be run on the high setting until the entire ceramic tile glows red. After lighting, however, it's pretty much "set-it-and-forget-it."


Besides being a heat source, this model Mr. Heater is portable and can be used indoors¹ with proper ventilation when powered by a one-pound cylinder. The small size (fourteen inches square and seven inches deep), light weight (less than ten pounds) and carrying handle make it easy to move from place to place. The low center of gravity makes it hard to tip over, and - unlike some heaters - the heater can be placed against a wall. It can be used on a floor or countertop and even wall-mounted.

I don't use mine with disposable cylinders, so I can't speak to the amount of time Mr. Heater runs on them, though the product literature claims they'll run three hours on high and six on low. Instead, I use the optional hose (about $15 for a five-footer and $24 for a twelve-footer) to power the heater. Nominally, that size cylinder allows 48 hours on low and 110 hours on high. Bringing a propane cylinder into an enclosed space is dangerous, however, so the Mr. Heater is rated for use indoors only with one-pound cylinders or if the large cylinder is sitting outdoors. A cunning brass coupling that allows refill of otherwise disposable one-pound cylinders from a twenty-pound cylinder is on my personal wish list.


Since it's readily portable, Mr Heater has long been a staple of ice fishermen and others who spend long hours in small, outdoor spaces during the winter months. It can be used outside, but it's not windproof - and is sensitive to being rained on. It is also part of an emergency kit for RVers, truckers, and drivers in cold and snowy climates. Be forewarned that performance is greatly diminished at altitude, and the heater is not recommended for use above 5000-7000 feet of elevation.





¹ Note: the heater is certified only for outdoor use in Canada, regardless of fuel source. Even though it has a low-oxygen sensor, you're probably well-advised to use a carbon monoxide detector as a backup when using it indoors - I have one in my workshop.