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Mr. Heater Little Buddy (F215100)
A fixed-output 3,800 BTU radiant heater with no dial, no adjustment, and the lightest carry weight in the Buddy lineup. Built for one person in a genuinely small enclosed space.
Best for: A single-person tent, ice-fishing shanty, car cab or small coop
- Lightest Buddy model at roughly 5.25 lb
- Lowest price point in the lineup
- Simplest possible operation — light it or don’t
- No low/high adjustment, ever
- 1 lb cylinder only, no 20 lb hose-connect option
- Undersized for anything bigger than a one-person space
Mr. Heater Portable Buddy (MH9BX)
The standard Buddy, with two settings — 4,000 and 9,000 BTU — and support for hose-connecting to a 20 lb tank with the right kit. More than double the Little Buddy’s coverage.
Best for: A mid-size tent, small cabin, garage corner, or two occupants
- Adjustable output covers small and mid-size spaces
- Can run off a 20 lb tank for longer sessions
- More flexible for changing conditions through a season
- Heavier and pricier than the Little Buddy
- Overkill for a one-person car cab or tiny shanty
- Still needs the optional hose kit bought separately for 20 lb tank use
Spec-by-spec comparison
| Factor | Mr. Heater Little Buddy (F215100) | Mr. Heater Portable Buddy (MH9BX) |
|---|---|---|
| BTU output | 3,800 BTU (fixed) | 4,000 / 9,000 BTU (two settings) |
| Coverage | Up to 95 sq ft | Up to 225 sq ft |
| Fuel source | 1 lb cylinder only | 1 lb cylinder, or 20 lb tank with hose kit |
| Runtime (per fuel unit) | Approx. 5–7 hrs per 1 lb cylinder | Approx. 3–7 hrs per 1 lb cylinder, depending on setting |
| Weight | Approx. 5.25 lb | Approx. 8.5 lb |
| Safety | ODS, tip-over shut-off | ODS, tip-over shut-off |
Both heaters share the same radiant design, oxygen depletion sensor and piezo ignition — the real question buyers actually have is which size fits the space they’re heating. Sizing down to the Little Buddy to save money, then discovering the space needs more than 3,800 BTU on a genuinely cold night, is the single most common regret aggregated across owner feedback for this lineup.
| Product | Best for | Buy |
|---|---|---|
| Mr. Heater 3,800 BTU Little Buddy Portable Radiant Propane Heater | Best for one person, small space | Check Price |
| Mr. Heater 9,000 BTU Portable Buddy Radiant Propane Heater | Best for mid-size spaces & flexibility | Check Price |
Top 3 Recommended
The One Real Difference: Fixed vs. Adjustable Output
The Little Buddy has exactly one setting: 3,800 BTU, on or off, with no dial in between. The standard Buddy has two: 4,000 BTU low and 9,000 BTU high, which means it can run at a very similar output to the Little Buddy on its low setting while still having a high setting in reserve for a colder night or a slightly bigger space. That reserve capacity is the entire case for spending more on the Buddy over the Little Buddy — it removes the guesswork about whether 3,800 BTU will actually be enough once the temperature drops.
Coverage Area: 95 sq ft vs. 225 sq ft
Mr. Heater rates the Little Buddy for up to 95 sq ft and the standard Buddy for up to 225 sq ft — more than double. In practice, both figures assume a reasonably enclosed space rather than an open area with drafts, so treat them as a ceiling rather than a guarantee. A one-person ice shanty or a car cab sits well within the Little Buddy’s rating with room to spare. A mid-size dome tent, a small cabin room, or two people sharing a space push toward or past the Little Buddy’s limit and land comfortably within the standard Buddy’s.
Fuel Source: 1 lb Only vs. 1 lb or 20 lb
This is the difference buyers notice least before purchase and most after. The Little Buddy is built exclusively for a disposable 1 lb cylinder, full stop — there is no hose-connect option for it at all. The standard Buddy also runs on 1 lb cylinders out of the box, but Mr. Heater sells an optional hose-and-filter kit that lets it hose-connect to a 20 lb tank instead, which cuts the cost per hour of fuel significantly for anyone running the heater regularly through a season. If you already own a 20 lb tank from a grill or another appliance, that alone can tip the decision toward the standard Buddy.
Weight and Portability
At roughly 5.25 lb, the Little Buddy is noticeably lighter than the standard Buddy’s roughly 8.5 lb, a difference that matters most to backpackers, hunters walking a distance to a stand, or anyone prioritizing pack weight above all else. For car camping, tailgating, or a job site where the heater rides in a vehicle rather than on a back, that weight gap matters far less than the coverage and fuel-flexibility differences above.
Winner by Use Case
Camping (one-person, small tent): Little Buddy — its 95 sq ft rating and lighter carry weight fit the use case exactly, and there’s no benefit to paying for capacity you won’t use.
Camping (two people or a mid-size tent): Standard Buddy — the 225 sq ft rating and 9,000 BTU high setting cover a colder night that would leave a Little Buddy struggling.
Ice fishing / hunting blind (solo): Little Buddy — a small, sealed shanty or blind rarely exceeds 95 sq ft, and the lighter weight is worth carrying in.
Garage corner or workshop use: Standard Buddy — the option to hose-connect a 20 lb tank makes longer sessions dramatically cheaper to run, and the higher BTU ceiling helps in a drafty space.
RV or van supplemental heat: Standard Buddy — most RV interiors run closer to or past 95 sq ft, and the adjustable low setting still sips fuel overnight when the high setting isn’t needed.
Pick the Little Buddy If…
- You’re heating one person in a space genuinely under 95 sq ft — a car cab, a small shanty, a one-person tent.
- Minimizing weight and cost matters more than having a high setting in reserve.
- You’re fine buying and carrying 1 lb cylinders exclusively, with no interest in a 20 lb tank setup.
Pick the Standard Buddy If…
- There’s any real chance the space needs more than 3,800 BTU on a cold night.
- You want the option to hose-connect a 20 lb tank later, even if you start on 1 lb cylinders.
- You’re heating more than one person, or a space in the 100–225 sq ft range.
What Owners Report After Buying the Wrong Size
Aggregated owner feedback across both models shows a consistent pattern: buyers who size down to the Little Buddy purely to save money, without checking their actual space against its 95 sq ft rating, are the ones most likely to end up buying a second, bigger Buddy within a season. Buyers who size up to the standard Buddy for a space that would have suited the Little Buddy rarely report regret — the extra capacity simply goes unused rather than causing a problem. That asymmetry is worth weighing against the roughly $20–$30 price gap between the two models.
Read the Full Reviews
For the complete spec breakdown, owner-reported pros and cons, and long-term ownership notes on each model individually, see our full Mr. Heater Little Buddy review and our full Mr. Heater Portable Buddy MH9BX review. For the complete lineup including the Big Buddy, see the Mr. Heater Buddy series guide.