Masterbuilt 40-inch ThermoTemp review: the propane cabinet that smokes where no cord reaches
Four racks and 960 square inches on propane, with a fuel gauge built into the regulator. Masterbuilt publishes a 375°F ceiling, not a range, and this review treats it as exactly that.
Verdict7 out of 10
Pros
- 960 square inches across four racks, with the metric figure published alongside
- Propane heat, so the smoker owes nothing to an extension cord
- Type 1 regulator with a fuel gauge, so tank level is a needle and not a shake test
- Assembled dimensions published: 28.7 inches wide, 22.8 deep, 53 tall
Cons
- 1 year warranty
- Up to 375°F is a ceiling, not a range. No minimum is published.
- No BTU rating, no burner count, no weight anywhere on the page
- No per-rack area, so the 960 total cannot be split four honest ways
Who this is for
- You smoke where there is no outlet: a detached patio, a cabin, a tailgate lot
- Your cooks stack. Four chrome-coated racks sharing 960 square inches suit butts and pans better than one wide grate.
Who should skip it
- An outlet is within reach. The 30-inch electric publishes a settable 100 to 275°F range instead of a bare ceiling.
- A 1 year warranty is not enough cover for you, and Masterbuilt publishes no BTU figure to size the burner against.
| Total cooking area | 960 sq inAcross the smoker's four racks. Masterbuilt does not publish a per-rack figure. |
|---|---|
| Smoking racks | 4 |
| Temperature range | Up to 375 °FDial maximum. Masterbuilt publishes no minimum, so this is a ceiling, not a range. |
| Grate material | Chrome-coated |
| Regulator | Type 1 regulator with fuel gauge |
| Assembled width | 28.7 in |
| Assembled depth | 22.8 inMasterbuilt labels this dimension 'Length'. It is the front-to-back measurement, shown here as depth. |
| Assembled height | 53 in |
| Warranty | 1 year warranty |
| Color | Black |
Specifications from the manufacturer and named third parties. Last read 2026-07-26.
The ThermoTemp solves one problem: the smoking spot with no outlet. It is a propane cabinet, 960 square inches across four racks, with a fuel gauge on the regulator and a published maximum of 375°F. Every figure here comes from Masterbuilt's product page, read 26 July 2026, and the gaps in that page get named as gaps. The one to hold onto from the start: up to 375°F is a ceiling. Masterbuilt publishes no floor, so nothing on this page treats it as a range.
How much cooking space does the Masterbuilt ThermoTemp have?
960 square inches, split across four chrome-coated smoking racks. Masterbuilt publishes the total and its metric equivalent, 0.62 square meters, but no per-rack figure, so how much of the 960 lands on any single rack is not on the page.
A vertical cabinet spends its space differently than a grill. Four stacked racks take sheet pans, rib racks laid flat and several butts at once, and nothing on them sits over direct flame. That is the format working as intended. This is a smoker, not a grill with a smoke setting.
One caution before the number wins a size contest on the pellet grills and smokers page. The 960 is a four-rack total. A maker that publishes only its main grate will post a smaller number and cook closer to this one than the totals suggest. Check what got counted before comparing.
How hot does the ThermoTemp propane smoker get?
Up to 375°F, and that is the entire published number. It is a dial maximum. Masterbuilt states no minimum, which means the page commits to a ceiling and nothing else, and a ceiling is not a range.
The distinction matters because a smoker earns its keep at the bottom of the dial, and the bottom is exactly what the page does not state. Masterbuilt does publish a settable range on its 30-inch electric, 100 to 275°F, and the temptation is to line those numbers up and read the propane box as simply hotter across the board. Resist it. One number is a range with a floor, the other is a ceiling with nothing under it, and they do not belong in the same column. The electric versus propane comparison keeps the two bases labeled where they sit side by side.
Can you run the ThermoTemp where there is no power?
Yes, and that is the reason it exists. Propane carries the whole cook, so the smoker can live on a detached patio, at a cabin or in a tailgate lot without a cord in sight. Electric cabinets and pellet grills both need an outlet before anything else happens. This one needs a tank.
The regulator is a Type 1 with a built-in fuel gauge. That puts remaining gas on a needle instead of a lift-and-shake estimate, and it matters more on a smoker than on a grill: a cook that runs out of fuel partway through is ruined, not delayed. Masterbuilt's page does not state a tank size or whether a tank is included, so sort the propane side out before the first cook. If your setup involves anything beyond connecting the supplied regulator to a standard tank, that is a job for a licensed gas professional, not a weekend project.
Will the ThermoTemp fit your space?
The published assembled dimensions are 28.7 inches wide, 22.8 inches deep and 53 inches tall. One labeling note: Masterbuilt calls the 22.8 figure "Length" on its page, and this site records it as depth, front to back, with the value exactly as published.
The height is the point of the format. A cabinet stacks its 960 square inches upward, so the ground it claims is a fraction of what a horizontal cooker with the same total would take.
Masterbuilt does not publish a weight. If the smoker has to climb deck stairs or ride in a truck bed, the page will not tell you what you are lifting. Get that number from Masterbuilt in writing before planning to move it alone.
What is the warranty on the ThermoTemp?
1 year. Masterbuilt's page states a 1 year warranty and nothing more granular, so read the terms for what each part carries. That is a short promise on an appliance meant to run all day, and it belongs in the decision before checkout rather than at the first failed part.
What does Masterbuilt not publish?
More than it should. No BTU rating, so there is no sizing the burner against a cold or windy shoulder season. No burner count. No weight. No per-rack area, so the 960 square inch total cannot be split into honest per-rack numbers. No temperature minimum, which is why this review keeps calling 375°F a ceiling. Where a figure is missing above, that is the reason: the manufacturer does not publish it, and this site does not fill gaps with guesses.
Should you buy the ThermoTemp or the electric Masterbuilt?
Buy the ThermoTemp if the cook happens beyond the reach of a cord. That is its entire case and it is a good one: four racks, 960 square inches, a fuel gauge to guard the long cook, and no dependence on a circuit.
Buy the 30-inch electric if an outlet is within reach. It publishes a settable range, 100 to 275°F, which is a commitment the propane page never makes, and plugging in takes the tank out of the logistics entirely.
If the fuel question itself is unsettled, start with the pellet versus electric versus propane guide. It sorts the three by what each needs before the first cook and what each gives up for it, and the ThermoTemp's answer to that first question is the shortest of the three: a tank, for the spot no cord reaches.