Mr. Heater Big Buddy Heater Review: Worth It? (October 2026)
The Mr. Heater Big Buddy suits portable supplemental heat when you need adjustable radiant warmth and can follow its safety instructions. It offers 4,000, 9,000 and 18,000 BTU settings, with two 1 lb cylinder capacity or an optional hose connection to a 20 lb tank.
On this page (10 sections)
- What does the Mr. Heater Big Buddy offer?
- How much space can the Big Buddy heat?
- Which fuel setup works for your plans?
- What accessories are needed for a 20 lb tank?
- What safety features does the Big Buddy have?
- How does the Big Buddy compare with a garage heater?
- Big Buddy vs Portable Buddy: which size makes sense?
- What are the Big Buddy's main trade-offs?
- How we assessed the Mr. Heater Big Buddy
- Is the Mr. Heater Big Buddy worth considering?
The Mr. Heater Big Buddy is a portable propane heater with 3 heat settings, a built-in fan and capacity for two 1 lb cylinders.
It suits supplemental heat where you want more output choices than a compact heater, and have a safe place to use it according to the manual.
Mr. Heater gives a maximum output of 18,000 BTU and coverage up to 450 sq. ft.
The brand also notes that indoor use isn't approved in Canada or Massachusetts, so check local rules and the manual before planning indoor use.
What does the Mr. Heater Big Buddy offer?
The Big Buddy offers 4,000, 9,000 and 18,000 BTU settings for choosing lower or higher heat output. Its radiant heating element warms nearby objects and people, while a built-in fan helps circulate warm air.
Mr. Heater: Best for adjustable portable heat
- 4,000, 9,000 and 18,000 BTU settings
- Radiant heat coverage up to 450 sq. ft.
- Electronic ignition
- Built-in fan
The Big Buddy combines 3 heat settings with a built-in fan and capacity for two 1 lb cylinders. It can also connect to a 20 lb tank with an optional Buddy hose and fuel filter.
Pros
- Three heat settings
- Built-in fan helps circulate warm air
- Electronic ignition
- Life Safety System includes low oxygen and tip-over shutoffs
Cons
- Hose and fuel filter are separate for a 20 lb tank setup
- Indoor use is not approved in Canada or Massachusetts
Electronic ignition starts the heater with a button. The model also has dual tank capacity for two 1 lb propane cylinders, plus the option to connect to a 20 lb tank with a Buddy hose and fuel filter.
Mr. Heater lists coverage of up to 450 sq. ft.
Treat that as a guide, not a promise that every room of that size will feel equally warm: ceiling height, drafts, insulation and the heater's position can all affect comfort.
Who should consider this Big Buddy?
Consider it if you want a portable propane heater with three output settings and a fan, and your planned space permits this type of heater. The multiple settings give you more choice than a single-output model.
A smaller model may be easier to place if you only need spot heat or have a tight storage area. Compare the [Mr.
Heater Portable Buddy heater review](/mr-heater-portable-buddy-reviews/) for a closer look at that alternative.
How much space can the Big Buddy heat?
The Big Buddy is rated for spaces up to 450 sq. ft. according to Mr. Heater, with actual comfort depending on the room and conditions.
A large, drafty garage may feel different from a smaller enclosed room even if both fall within that area figure.
BTU describes heat output, not a guarantee of room temperature. Our guide explains what BTU means in a heater and how to use the number when comparing models.
Think about the area you need to warm, whether heat should reach one work zone or a wider area, and how much cold air enters. In a garage, also consider where the heater can sit while keeping the required clearances around it.
For a broader comparison based on different spaces and fuel setups, see our best portable propane heater guide.
Which fuel setup works for your plans?
The Big Buddy can use two 1 lb propane cylinders or connect to a 20 lb tank with an optional Buddy hose and fuel filter. Your choice depends on how long you want to run it, how often you can change cylinders and whether a larger tank can be placed safely.
A larger tank can reduce the need to swap small cylinders, but hose length and routing matter. Keep the tank positioned as the manual directs, away from heat and protected from damage.
The small tank propane heater guide explains the practical trade-offs when you want a smaller fuel source. Before connecting any hose, verify the exact heater model and permitted accessories.
What accessories are needed for a 20 lb tank?
A 20 lb tank setup needs a compatible Buddy hose and fuel filter. Mr.
Heater says the Big Buddy can connect to a 20 lb tank using those optional accessories, which are sold separately.
The filter does not connect directly to the propane tank. Follow the heater instructions for the connection order, and don't substitute an accessory unless Mr.
Heater approves it for your model.
The REDPANT adapter's listed compatibility includes the Big Buddy MH18B. Check your heater's model number and manual, since using unauthorized accessories can cause serious injury and may void the heater warranty.
What safety features does the Big Buddy have?
The Big Buddy includes low oxygen shutoff, tip-over shutdown and self-extinguishing protection as part of its Life Safety System. Those features add safeguards, but they don't remove the need to follow the manual's ventilation, clearance and operating directions.
Mr. Heater says the heater is designed and approved for indoor and outdoor use, except indoor use is not approved in Canada or Massachusetts.
Compare indoor propane heaters when considering other models.
Confirm local requirements before using it inside, and use a carbon monoxide alarm where required or recommended by the manual and local authorities.
Keep the heater on a stable surface and maintain the specified clearance from people, fuel, furnishings and other items. Don't leave it unattended or use it in a space the manual excludes.
The Mr. Heater Buddy vs Big Buddy comparison can help you weigh the larger model against a smaller Buddy option, but the right choice still depends on your space and safe operating conditions.
How does the Big Buddy compare with a garage heater?
The Big Buddy is a portable supplemental heater, while a garage heater may be a better fit for regular whole-room heating. For a workshop or garage you use often, compare fuel, ventilation, mounting and operating requirements before choosing.
A portable propane heater can be moved to different permitted locations, but it still needs clearance, ventilation and a suitable fuel setup each time. A permanently installed unit may offer a different kind of convenience, subject to installation requirements.
Compare an electric fireplace vs. a space heater if you are weighing fixed electric heat against a portable heater. For plug-in room options, compare Lasko space heaters.
Use our guide to the best heater for a garage to compare options for that room. Check whether the heater is suitable for the exact garage conditions and planned use.
Big Buddy vs Portable Buddy: which size makes sense?
Choose the Big Buddy if you need three heat settings up to 18,000 BTU and the larger coverage rating. A smaller Buddy may make more sense for occasional spot heating or when portability and compact storage matter more than maximum output.
The best choice isn't only about the highest BTU figure. Think about where you'll set the heater, how often you'll move it, the available fuel source and whether the space allows safe operation.
If you are comparing indoor fuel options, see small kerosene heaters for indoor use.
Our Mr. Heater Buddy vs Big Buddy guide compares their use cases.
For the smaller unit's specific features, read the Portable Buddy heater review.
What are the Big Buddy's main trade-offs?
The Big Buddy's main strengths are adjustable output, a fan and flexible fuel options. Its main planning costs are space, separate accessories for a larger tank and strict attention to safe use.
| Big Buddy detail | What it means for you |
|---|---|
| Heat settings | 4,000, 9,000 and 18,000 BTU |
| Coverage | Up to 450 sq. ft., according to Mr. Heater |
| Heat type | Radiant |
| Air movement | Built-in fan |
| Ignition | Electronic |
| Fuel | Propane |
| Cylinder capacity | Two 1 lb cylinders |
| Larger tank option | 20 lb tank with optional Buddy hose and fuel filter |
| Safety features | Low oxygen shutoff, tip-over shutdown and self-extinguishing protection |
| Indoor use | Not approved in Canada or Massachusetts |
This model is a stronger match for someone who expects to use different output levels and wants the option of a larger tank connection. It's less compelling if a compact heater covers your needs or if your planned location doesn't meet its operating instructions.
How we assessed the Mr. Heater Big Buddy
We compared the Big Buddy's stated heat settings, coverage, fuel options and safety features against the needs of portable propane heating. Our score weighs those features against the flexibility a reader may want from a portable heater.
The key buying checks are whether your space is suitable, whether you need the fan and multiple settings, and whether you can source the correct hose and filter for a larger tank. Verify the heater model and accessory instructions before setup.
Is the Mr. Heater Big Buddy worth considering?
The Big Buddy is worth considering if you need portable propane heat with 3 settings and a larger tank option. Choose a smaller Buddy if you mainly need compact spot heating, or look at a garage-specific heater for regular whole-room use.
The decision rule is straightforward: pick the Big Buddy for more output choices and broader stated coverage, provided your location and fuel plan meet its instructions. Read our portable propane heater comparison to compare it with other types.
Frequently asked questions
How many BTU does the Mr. Heater Big Buddy produce?
The Big Buddy has 4,000, 9,000 and 18,000 BTU heat settings. Mr.
Heater gives coverage of up to 450 sq. ft., but room shape, insulation, air movement and outdoor conditions affect how warmth feels.
Use the setting that fits the space and follow the manual.
Can the Big Buddy run from a 20 lb propane tank?
Yes, it can connect to a 20 lb tank using an optional Buddy hose and fuel filter. The heater also holds two 1 lb propane cylinders.
Confirm the correct hose, filter and setup in the manual before connecting fuel.
Is the Mr. Heater Big Buddy approved for indoor use?
Mr. Heater describes the Big Buddy as approved for indoor and outdoor use, with indoor use not approved in Canada or Massachusetts.
Local rules and the heater manual matter, and the built-in safety features don't replace ventilation, clearances or carbon monoxide precautions.
Does the Big Buddy have a fan?
Yes, the Big Buddy has a built-in high-powered fan to help circulate warm air. It also produces radiant heat at 3 settings.
Consider whether fan-assisted circulation suits your space, and check the manual for electrical or operating requirements.
