Mr. Heater MH18BRV Big Buddy Portable Propane Heater - Indoor Safe

In this review of the Mr. Heater MH18BRV Big Buddy, the bottom line is simple: it is a capable, portable propane heater for enclosed spaces that need reliable warmth. The unit is best for campers, cabins, garages, and tents where the choice of three heat settings and a mix of radiant and convection heating provide flexible comfort. The review finds it easy to light and carry, with clear safety features, and particularly valuable when running off 1 lb disposable cylinders or a remote 20 lb supply with an added hose.

Key Features

• Three heat settings: High, medium, and low modes let you dial in output of 4,000, 9,000, or 18,000 BTU to match the size of the space and desired warmth.
• Radiant plus fan-assisted heat: The patented radiant design with an integrated fan blends radiant and convection heating for more even warmth across a room up to about 450 sq ft.
• Dual cylinder connection: Two swivel regulators accept 1 lb disposable cylinders and also allow connection to a remote 20 lb cylinder with a hose and filter for extended runtime.
• Simple ignition: A single control start knob with a Piezo sparking mechanism makes lighting straightforward and reliable without extra tools.
• Safety features: Built-in Oxygen Depletion Sensor (ODS) and automatic tip-over shutoff add important protection when used in enclosed or mobile spaces.
• Portable design: An easy-grip handle and heavy-duty wire guard make the unit rugged for travel and placement in sheds, porches, or hunting blinds.

Who It's For

The MH18BRV suits RV owners, weekend campers, and cabin users who need a portable heater that can run from disposable 1 lb cylinders or be adapted to a larger tank. It is also a solid choice for hobby garages, sheds, and temporary workspaces where quick, directed heat and portability matter.

It is not ideal for long unattended indoor heating of a primary living area without ventilation or for users who need built-in long-term fuel supply without purchasing a hose and filter; those seeking whole-home heating or plug-in electric convenience should consider different options.

Pros & Cons

Pros

• Flexible 4,000 to 18,000 BTU output covers small to mid-size spaces effectively.
• Easy to light and operate with one control knob and Piezo ignition.
• Portable build with handle and wire guard makes it travel-ready and durable.
• Safety features like ODS and tip-over shutoff provide added peace of mind indoors.

Cons

• Fuel efficiency and fan size receive mixed customer feedback, so runtime and airflow expectations may vary.
• Hose, filter, and remote tank adapter are not included if you want extended run times from a 20 lb cylinder.

Specifications

Brand	Mr. Heater
Output	4,000, 9,000, or 18,000 BTU per hour
Coverage	Approximately 450 sq ft
Fuel	Propane (1 lb cylinders or 20 lb with hose)
Runtime	Up to 3.6 hours on low, 1.8 hours on high (using 1 lb cylinder)
Safety	ODS and accidental tip-over shutoff

Our Verdict

The Mr. Heater MH18BRV Big Buddy is a practical, value-oriented portable propane heater for campers, cabins, and workspaces that need flexible heat output and dependable safety features. It offers an effective mix of radiant and fan-assisted heat and convenient portability, though buyers should budget for a hose and filter if they plan to use a remote tank for longer runtimes.

Frequently Asked Questions

Can this heater be used indoors?
Yes, the unit is designed for indoor-safe use with an Oxygen Depletion Sensor and tip-over shutoff, but adequate ventilation is still recommended.

What fuel does it use?
The heater runs on propane and connects to two 1 lb disposable cylinders or can attach to a 20 lb cylinder with a separate hose and filter.

How large of an area can it heat?
Mr. Heater rates it for about 450 sq ft when set and positioned appropriately, with the three BTU settings allowing adjustment to room size.