Mr. Heater Big Buddy Propane Heater: Transform Your Cold Garage Into a Comfortable Workshop

The Mr. Heater Big Buddy Propane Heater is the most popular portable propane heater in the United States, and for Boston-area homeowners, contractors, and garage workshop users, it solves a specific winter comfort problem that electric space heaters cannot. Boston’s cold winters, high electricity costs, and the prevalence of uninsulated garages in older New England homes make the Big Buddy a genuinely practical heating solution for millions of households. This comprehensive review covers everything Boston homeowners need to know about the Mr. Heater Big Buddy: output, safety, fuel costs, performance in cold conditions, and the specific New England use cases where it excels.

Mr. Heater Big Buddy specifications

The Mr. Heater Big Buddy delivers 4,000, 9,000, or 18,000 BTU output, three heat settings that allow precise control from maintaining above-freezing temperatures in an unoccupied garage to comfortable workshop heat for active use. The 18,000 BTU maximum output heats spaces up to 450 square feet, making it capable of heating a standard 2-car garage in mild conditions or a 1-car garage in Boston’s coldest weather. Runtime on two 1-lb propane cylinders runs 3-6 hours at maximum output depending on temperature conditions. The built-in fan (fan-forced heat) distributes warm air more effectively than convection-only heaters, reducing the cold stratification common in garages where heat pools at the ceiling.

The Big Buddy connects to standard 1-lb propane cylinders directly or to larger 20-lb tanks via an optional hose and filter (sold separately but essential for regular garage use, the cost per BTU from 20-lb tanks is dramatically lower than 1-lb cylinders). The Oxygen Depletion Sensor (ODS) automatically shuts the heater off if oxygen levels drop below safe thresholds, the critical safety feature that makes indoor propane use possible when proper ventilation is maintained. The tip-over shutoff activates if the heater is knocked over. Both safety systems are passive and automatic, they do not require user action to function.

Boston garage heating context

Boston’s climate creates specific garage heating challenges that make the Big Buddy more valuable here than in milder markets. Average January temperatures of 29F (-2C) mean unheated garages drop below freezing regularly from November through March, damaging stored fluids, making tool use painful, and creating conditions where vehicles need extended warm-up time before safe operation. Boston’s older housing stock, the vast majority of the metro’s garages are attached to triple-deckers, colonials, and Victorian homes built before 1970, means most garages have minimal insulation, no dedicated heating systems, and the kind of air infiltration that makes electric space heaters inadequate for anything beyond localized warming.

The Big Buddy’s 18,000 BTU maximum output provides approximately 3x the heating power of a typical 1,500-watt electric space heater, the relevant comparison for Boston homeowners evaluating heating options. In a minimally insulated 1-car garage (approximately 200 square feet) during a 20F Boston winter day, the Big Buddy at maximum output maintains comfortable workshop temperatures of 55-65F within 20-30 minutes of startup. An electric space heater in the same conditions struggles to maintain 45F. For garage workshop use, woodworking, automotive maintenance, home improvement projects, the temperature difference is the difference between comfortable productivity and miserable endurance.

Fuel costs: propane vs. electricity in Massachusetts

Massachusetts has some of the highest electricity rates in the continental United States, averaging $0.25-$0.29 per kilowatt-hour in 2026, more than double the national average. This pricing makes electric space heaters significantly more expensive to operate than propane alternatives for extended heating sessions. A 1,500-watt electric space heater running for 4 hours costs approximately $1.50-$1.75 in Massachusetts electricity. The Big Buddy at 18,000 BTU (approximately 5,000 watts equivalent heat output) running on a 20-lb propane tank costs approximately $0.80-$1.00 per hour at current Massachusetts propane prices of $3.50-$4.00 per gallon, delivering 3x more heat at roughly 2.5x the cost, representing meaningfully better value per BTU delivered.

The economics shift when comparing to natural gas heat, where available. Homes with natural gas service in Boston pay approximately $1.50-$2.00 per therm, significantly cheaper than propane on a per-BTU basis. For homeowners with natural gas service who can extend a gas line to the garage, a dedicated gas heater is typically more cost-effective than propane for regular, extended use. But gas line extension involves permits, licensed plumber work, and upfront costs of $1,500-$3,000+, making the Big Buddy the economically rational choice for moderate use (2-4 hours per session, 3-4 days per week during winter months).

Safety in Boston homes

Propane heater safety in enclosed spaces is the critical consideration that separates responsible Big Buddy use from dangerous use. The Mr. Heater Big Buddy is rated for indoor use with proper ventilation, this designation is based on the ODS shutoff system, not an assertion that the heater can be used in sealed spaces without consequence. Carbon monoxide is produced by any combustion heater, including propane. In a tightly sealed garage, carbon monoxide levels can rise to dangerous concentrations within 20-30 minutes of heater operation. The ODS sensor detects oxygen depletion (a proxy for CO buildup) and shuts the heater off, but this is a last-resort safety measure, not a substitute for ventilation.

The correct safety protocol for Big Buddy use in Boston garages is straightforward: crack the garage door 2-3 inches to maintain fresh air exchange, install a battery-powered carbon monoxide detector (required by Massachusetts law in all homes with fuel-burning appliances) in the garage, and never leave the heater running in an unoccupied space. These three measures make Big Buddy use in Boston garages genuinely safe. Boston’s building code requires CO detectors in garages attached to living spaces, compliance with this requirement is both legally mandatory and practically essential when operating any combustion heating device. The Massachusetts State Fire Marshal recommends leaving at least one door or window cracked during propane heater operation in garages.

Mr. Heater Big Buddy vs. competitors

The Big Buddy’s primary competitors are the Mr. Heater Little Buddy (4,000 BTU, insufficient for Boston garage heating), the Dyna-Glo 18,000 BTU Portable Propane Heater, and the DeWalt DXH45FA Forced Air Propane Heater. The Dyna-Glo offers comparable BTU output at a lower price point but lacks the Big Buddy’s fan-forced heat distribution and has a less refined safety system. The DeWalt forced-air heater delivers higher BTU output (45,000 BTU) suitable for larger uninsulated spaces but is substantially louder, consumes propane significantly faster, and is less suited to occupied workshop use due to the noise and forced-air design.

The Big Buddy’s advantages over the competitive field are the combination of fan-forced heat distribution, dual ODS and tip-over safety systems, the versatile 3-setting output range, and the Mr. Heater brand’s established reliability in New England contractor and homeowner use. The brand is ubiquitous at New England hardware stores including Home Depot, Lowe’s, and independent lumber yards, replacement parts, accessories (hose and filter for 20-lb tank connection, dust filter for construction site use), and warranty service are readily available throughout the Boston metro area.

Best Boston use cases

The Mr. Heater Big Buddy is most valuable in Boston for: garage workshops where woodworking, automotive maintenance, or home improvement projects require extended time in unheated spaces during winter months; construction sites where temporary heat is needed during cold-weather work (the Big Buddy is a standard fixture on Boston construction sites from November through March); seasonal spaces like screened porches, sunrooms, or garden sheds that lack permanent heating but are used during shoulder seasons; and emergency backup heating for homes during power outages, a genuinely practical consideration in Greater Boston where winter nor’easters can leave neighborhoods without power for 24-48 hours.

For Boston landlords, the Big Buddy is a practical solution for heating common areas during maintenance work, keeping pipes from freezing in unheated utility spaces during extreme cold, and providing supplemental heat during HVAC system failures while awaiting repair. Massachusetts landlord-tenant law requires landlords to maintain rental unit temperatures above 68F from September 15 through June 15, a portable propane heater is a legitimate emergency measure while permanent heating systems are repaired, provided CO safety protocols are followed. For comprehensive landlord tool recommendations, see our complete landlord tools guide and our essential landlord tools list. For Boston homeowner resources, see our Boston market report and our smart home devices guide.

Final verdict

The Mr. Heater Big Buddy is the correct portable propane heater recommendation for Boston homeowners, contractors, and landlords who need reliable winter heating for uninsulated or temporary spaces. The 18,000 BTU maximum output handles Boston’s coldest winter conditions in standard garage and workshop applications. The dual safety systems (ODS and tip-over shutoff) make it the safest option in its class for occupied use. The fan-forced heat distribution outperforms convection-only alternatives in the large, poorly insulated spaces typical of Greater Boston’s older housing stock. The fuel economics are favorable relative to Massachusetts’s high electricity rates for moderate-use applications. And the brand’s availability and support network throughout the Boston metro make it the practical choice over less-established competitors. Used with proper ventilation and a functioning CO detector, both simple and inexpensive to implement, the Mr. Heater Big Buddy is a genuinely valuable winter tool for Boston’s challenging climate.

Propane tank options and fuel logistics

The Big Buddy’s fuel logistics are worth understanding before purchase, the choice between 1-lb cylinders and 20-lb tanks significantly affects the economics and convenience of regular use. The 1-lb cylinders included with the heater and sold at most Boston hardware stores cost $5-7 each and provide approximately 1.5-3 hours of runtime at maximum output. For occasional use, a single afternoon project, an emergency heating situation, 1-lb cylinders are convenient and require no additional accessories. For regular garage workshop use of 4+ hours per week throughout the Boston winter, 1-lb cylinders become expensive quickly: $15-25 per weekend of heating adds up to $150-300 over a typical Boston winter season.

The 20-lb propane tank solution, using the Mr. Heater 5-foot hose and filter accessory (approximately $20) to connect the Big Buddy to a standard grill-size propane tank, dramatically improves the fuel economics. A 20-lb tank costs $25-35 to fill at Boston-area propane fill stations (U-Haul, hardware stores, and dedicated propane suppliers in the metro) and provides approximately 20-40 hours of runtime at maximum output, roughly 8-15 heating sessions. The per-session cost drops from $15-25 with 1-lb cylinders to $2-4 with 20-lb tanks. The hose and filter accessory is a worthwhile $20 investment for anyone planning regular use. Note that the filter is required when connecting to larger tanks, it prevents oil contamination from bulk propane tanks from reaching the heater’s ODS sensor.

Performance in extreme Boston cold

The Big Buddy’s performance in Boston’s coldest conditions, the January and February cold snaps where temperatures drop to single digits or below zero, differs from its performance in typical winter conditions. Propane pressure decreases as tank temperature drops, reducing the heater’s effective output at very low temperatures. A 20-lb tank stored outside in below-zero conditions may produce reduced flame at maximum output. The solution is simple: store the propane tank inside the garage (not inside the living space) where the ambient temperature stays above freezing. Tanks stored at 40F or above maintain full pressure. Boston homeowners who store their Big Buddy and tank in an unheated garage during the season should bring the tank inside the home’s conditioned space for an hour before use during extreme cold snaps to restore full pressure.

The Big Buddy’s igniter, a piezoelectric spark ignition, can be less reliable in very cold conditions, sometimes requiring 2-3 attempts to light. This is a characteristic of piezoelectric igniters generally rather than a specific Big Buddy fault. Keeping a long-handled lighter as a backup ignition source is a practical precaution for Boston winter use. Once lit, the heater operates normally regardless of ambient temperature, it’s the ignition process that cold affects, not the combustion. For Boston homeowners evaluating the Big Buddy against other winter heating solutions, see our smart home devices guide and our essential landlord tools guide for complementary product recommendations suited to Greater Boston’s climate and housing stock.