Mr. Heater MH540T Review — a compact propane heater that brings real heat to cold garages, patios, and tailgates

The Original 540-Degree 45,000 BTU Tank Top Radiant Propane Heater has a very specific personality: it doesn’t try to be subtle, and it definitely doesn’t try to be “smart.” It’s the kind of heater people buy because they’re tired of freezing in the garage, tired of a cold patio ruining the vibe, or tired of loud forced-air heaters that sound like a leaf blower with ambition.

This review is built from what owners consistently report after using it in real places — garages, workshops, screened porches (with ventilation), campsites, tailgates, and outdoor pop-up setups.

TL;DR verdict

If you want a lot of radiant heat without electricity, this is one of the most-loved “strap it to a propane tank and get warm” solutions out there. People rave about the heat output, the simplicity, and how fast it makes a cold space feel usable.

Just don’t expect miracles in wind, and don’t expect “gentle background warmth.” This thing is more like: step back two feet or you’ll start negotiating with the thermostat gods.

The kind of heat it delivers (and why it feels different)

Most electric space heaters warm the air. This heater warms you — and anything nearby — with radiant heat. That’s why customers keep describing it as “campfire-like” and why it can feel intense even when the air temperature hasn’t fully caught up yet.

In garages and workshops, that radiant effect is exactly what people want. Multiple owners describe flipping it on, doing a quick warm-up on High, and then dropping down to Low once the space is comfortable.

Outdoors, the same thing applies: it’s less about heating the entire world and more about creating a warm zone where people naturally gather.

Heat direction: “360°” is real, but aiming still matters

One of the most repeated user tips is also the simplest: tilt the head toward people.

A lot of owners say the warmth is noticeable all around, but the strongest heat tends to rise, so you get better results when you angle it toward chairs, a workbench, or the area where everyone’s standing. Some people even get creative and add a DIY reflector to push heat down and outward — basically turning “nice heat” into “why am I sweating in December?”

If you’re using it for a group, the popular move is to keep it more upright so everyone gets a share. If you’re using it for one side of a space, tilting it makes a bigger difference than most people expect.

Real-world speed: why people keep calling it a “life saver”

The most consistent praise is how quickly it changes the mood of a cold space.

Garage users often describe going from “I can see my breath” to “okay, I can work” in a short window — especially compared to electric options that take longer to feel effective in larger, drafty areas. Tailgaters and outdoor event folks describe it as the reason they can stay outside longer without layering up like they’re crossing Antarctica.

There’s a pattern in the comments: people don’t just like it — they buy a second one, or they buy it as a gift after friends experience it once.

Noise: blessedly simple, blessedly quiet

A lot of folks compare it to torpedo-style heaters or anything forced-air. The difference is immediate: no fan roar, no “engine room” sound, no rattling duct vibe.

You’ll still hear that it’s operating, but customers consistently describe it as quiet enough for conversation, which is exactly what you want on a patio or at a tailgate.

Propane use: the tradeoff for big heat

Here’s the honest part: big heat costs fuel.

Plenty of owners say it runs through propane faster than they’d like on High. Others are perfectly happy with the runtime because the heat is so strong they don’t need to run it on High for long. A common strategy is:

• High for a quick warm-up
• Medium for “get comfortable”
• Low for maintaining the zone

A few people also mention dialing the tank valve carefully to fine-tune output, but if you’re not comfortable doing that, stick with the built-in settings and focus on positioning.

Wind and weather: the thing no one can fully cheat

The number one “outdoor reality check” is wind.

Some users report flame-outs on windy days, and many say it works best when you can shield it — under a canopy (with safe spacing), near a wall that blocks gusts, or simply positioned so it’s not taking wind head-on. If you’re buying it for open, windy spaces, plan for that and treat wind protection as part of the setup.

Ease of use: easy overall, but the first ignition can test your patience

Most owners describe setup as quick: attach it, tighten connections, and you’re basically there.

The part that catches people is lighting the first time. Several reviews mention needing to hold the button longer until the burner glows more fully — and that after the first “break-in” style light, it starts much faster going forward.

Also worth knowing: a few buyers mention the connection and threading can feel awkward at first, and more than one person warns about the reverse-thread behavior on certain fittings. If you’re setting it up in a freezing garage with numb fingers, you’ll understand why people bring that up.

Build quality and durability: mostly strong, with a few outliers

The dominant theme is “this feels heavy duty.” People like the solid feel, and a lot of buyers report using it season after season.

That said, a minority report issues: occasional weld failures, guards breaking after lots of heating cycles, or flow-safety/regulator quirks that needed a replacement part. Customer service experiences are often positive in those cases — several owners say parts were replaced quickly — but it’s still worth knowing those stories exist.

Safety: read this part like you mean it

Customers are very clear about two things:

• It gets extremely hot.
• It sits at a height that can be risky around kids and pets.

People love the warmth, but several reviews basically say: “I wouldn’t run this around small kids.” That’s not drama — it’s realism.

Owners who use it in garages or semi-enclosed areas frequently mention cracked doors, fresh airflow, and CO detectors. The manufacturer also emphasizes ventilation and safe clearances in the manual.

If your use case involves kids, pets, tight spaces, or anything flammable nearby, this is not the heater you casually “set and forget.”

Who this is for

You’ll probably love it if you want:

• Big radiant heat for a garage, workshop, patio, tailgate, or camp setup
• A heater that works without electricity
• Quiet operation and simple controls
• Something that creates a warm “gather here” zone fast

You should skip it (or choose a different style) if you need:

• Gentle, background warmth for long periods without burning fuel
• A heater that performs the same in open wind
• Something you feel comfortable using around small kids or curious pets
• True “whole space heating” for large, open-plan areas