Last updated: February 22, 2026

Mr. Heater Big Buddy MH18B Portable Propane Heater: Can It Handle Your Garage in 2026?

Name: Mr. Heater Big Buddy Indoor/Outdoor Portable Propane Heater
Brand: Mr. Heater
SKU: B00FPL6CNS
Price: 29.99 USD
Availability: InStock
Rating: 4.5 (842 reviews)

The Big Buddy delivers 18,000 BTU at $29.99 and covers 450 sq ft. It is the top pick for garages, workshops, and outdoor spaces that need serious heat fast.

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Key Specifications

Best For

Indoor/Outdoor

Best For

How this product scores for different use cases

Our Verdict

The Big Buddy puts out 18,000 BTU for $29.99. It covers up to 450 square feet. That is outstanding output for the price.

This heater runs on propane, not electricity. You need to keep fuel canisters on hand. Propane costs more per hour than running an electric heater.

Safety coverage is partial. The ODS sensor and tip-over protection are real and useful safeguards. But there is no overheat shutoff.

This heater belongs in garages, workshops, and outdoor spaces. It lacks a thermostat and timer for bedroom or office use. Pick it for raw portable heat output, not precise climate control.

63 Overall Score

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What We Like

Puts out up to 18,000 BTU and heats spaces up to 450 sq ft.
Three heat settings give you 4,000, 9,000, or 18,000 BTU options.
Oxygen Depletion Sensor shuts the unit off automatically if oxygen drops too low.
Tip-over protection cuts power instantly if the heater falls over.
Priced at $29.99 with both indoor and outdoor use approved.

What Could Be Better

No thermostat means you cannot set and hold a specific temperature.
No overheat protection sensor to guard against excessive surface heat.
No timer to schedule automatic on or off cycles.
No remote control or Wi-Fi means all adjustments require walking to the unit.
No oscillation, so heat does not distribute evenly across a wide room.

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Standout Features

18,000 BTU maximum heat output

Most portable propane heaters at this price cap out at 9,000 BTU. This unit doubles that output while covering 450 sq ft.

Oxygen Depletion Sensor (ODS)

Few portable heaters under $50 include an ODS. It cuts power automatically when oxygen levels drop to an unsafe level.

Three-level heat control: 4,000, 9,000, and 18,000 BTU

Most budget heaters offer only two heat settings. Three levels let you match output to the actual size of your space.

Full Specifications

Additional Info

Assembly

Frequently Asked Questions

Common questions about Mr. Heater Big Buddy Indoor/Outdoor Portable Propane Heater

How large of a space can the Big Buddy heat?

It heats up to 450 square feet at the 18,000 BTU maximum setting. Lower settings cover smaller areas and use less fuel.

Is it safe to use indoors?

The manufacturer rates it as indoor-safe. It includes an Oxygen Depletion Sensor that shuts the unit off if oxygen levels drop. Always use it in a ventilated space and follow all propane safety guidelines.

What fuel does the Big Buddy use?

It runs on propane. You can connect standard 1-lb propane cylinders directly or attach a larger tank with an optional hose adapter.

Can I control the temperature automatically?

No. The Big Buddy uses a four-position manual control knob. There is no thermostat, so you must adjust the heat level by hand.

Is this heater good for camping or tailgating?

Yes. It has a fold-down carry handle and runs on portable 1-lb propane cylinders. This makes it practical for camping, tailgating, job sites, and patios.