DeWalt 3.3 kW Forced Air Electric Construction Heater

I rolled the DeWalt 3.3kW heater into my garage on a 20°F morning with realistic expectations: at 3,300 watts, this is a modest-capacity, 240-volt jobsite heater meant for steady, targeted warmth rather than instant, space-filling heat. After a few weeks of use in a couple of different spaces, it’s clear where this heater shines—and where it runs up against the limits of its output and design choices.

Setup and power: know your circuit

This heater is 240 VAC, single-phase only. It draws about 13.75 amps and belongs on a dedicated 2-pole, 20-amp breaker. If you’ve never installed a 240-volt tool in your shop, budget time and a licensed electrician for proper wiring and a suitable receptacle. My unit arrived without a power cord, which is by design—some retailers supply one, some don’t—so plan on sourcing a 12 AWG, 3-conductor cord and an appropriate 240V plug if you want it plug-in ready instead of hardwired.

A practical note from my install: the factory strain relief/grommet opening on the housing is tight for a robust 12/3 cord with a thick jacket. I replaced it with a larger, code-compliant cord connector to get a proper mechanical grip on the cable. It’s not a showstopper, but it does add friction to the setup if you’re doing a clean, to-code corded install.

Build and design

The heater itself feels solid and jobsite-ready at 19 pounds. The oversized handle is genuinely useful—balanced, easy to grab with gloves, and stiff enough that the unit doesn’t sway. DeWalt uses dual supports on the heating coils, and the benefit shows up in transport: less pinging and fewer rattles than the typical “open coil in a can” heater when you move it around.

Controls are recessed behind a lip, which is great for a shop environment where knobs and switches can get bumped. The illuminated power switch is obvious from across the room, and the fault LED adds a layer of confidence. I never tripped a fault condition in use, but it’s good to have that indicator spelled out on the front panel.

Fit and finish are what I expect at this price point: sturdy casing, neat seams, and a grille that doesn’t ring like a tuning fork. There’s no dust filter, so expect to blow it out periodically if you run it in a dirty space.

Performance and heat output

At 3.3 kW (about 11,260 BTU/hr) pushing roughly 250 CFM, this heater is squarely in the “keep a bay workable” category, not the “turn a drafty barn into a sauna” category. In my 380 sq ft, moderately insulated garage with an 8.5-foot ceiling, I consistently saw a 10–15°F rise in the first hour from a cold start, and could hold the mid-50s when outside temps sat in the 20s. In a tighter, well-insulated ~200 sq ft shop room, it brought the space into the low 60s from near freezing in a couple of hours and maintained that without drama.

Air leaving the grille is genuinely hot and you can feel a strong, focused stream several feet out, though at 250 CFM this isn’t a high-velocity blower that will churn an entire room quickly. It’s best used aimed at where you’re working—bench, vehicle bay, or tool area—while the space gradually warms overall.

A quick myth-buster: the heating coils in this type of forced-air electric unit often won’t glow bright red in a well-lit space, even when they’re delivering full output. Mine showed only a faint dull glow in a dark room. What matters is the outlet air temperature and the room rise—both of which were consistent with a 3.3 kW element.

Thermostat and controls

The thermostat range is wide (roughly 25°F to 95°F), which makes this useful both for freeze protection and for comfortable shop temps. The control is simple: set it and the element cycles to maintain the target. In practice, it held a steady temperature within a few degrees and didn’t short-cycle. For a small heater, it’s a handy set-and-forget experience, and the ability to keep a cold space just above freezing is particularly valuable for protecting finishes, adhesives, and stored liquids.

Noise and airflow

Noise is moderate—typical “shop fan” sound but not shrill. I could comfortably carry on a conversation a few feet away. The airflow is smooth rather than turbulent; you don’t get the harsh, high-pitched whine you sometimes hear from compact blowers. On a slab, the unit sits planted and doesn’t resonate.

Safety and unattended use

No combustion, no fumes, no open flame—one of the big advantages of electric heat in a closed shop. The unit is certified for unattended operation, and while I still treat any heater with respect (keep clearances, don’t drape rags near the grille, blow out dust periodically), it’s reassuring to have that certification. The recessed controls and illuminated switch also help reduce “did I leave it on?” anxiety when you’re wrapping up.

Efficiency and operating cost

At point of use, electric heat is effectively 100% efficient. The practical question is cost. At a typical $0.15/kWh utility rate, you’re looking at roughly $0.50/hour to run at full draw. If you’re trying to bring a large, poorly insulated space up to comfort temps daily, that adds up. If you’re using it for spot heat where you’re working or for keeping a small workspace above freezing, the cost is reasonable and predictable.

Where it fits—and where it doesn’t

This heater is a strong fit if:
- You have a 240V, 20A circuit available.
- Your space is small-to-medium and at least somewhat insulated.
- You value clean, fume-free, thermostat-controlled heat.
- You want jobsite durability with simple controls.

It’s not the right tool if:
- You’re trying to heat a large, leaky shop from near-zero temps to shirtsleeve comfort quickly.
- You don’t have 240V service and don’t plan to add it.
- You expect the airflow of a torpedo heater or the output of a 5–10 kW unit.

There’s also a niche benefit here: many 240V shop heaters jump straight to 5 kW and require a 30A circuit. This 3.3 kW model threads the needle—more oomph than a typical 120V heater, but still compatible with a 20A 240V breaker that’s common in smaller shops.

Quirks and wish list

• The lack of a standardized, included power cord makes sense for flexibility, but I’d like to see a clear, generous strain relief that’s sized for typical 12/3 SO-type cords. As it stands, expect to swap the factory grommet/connector for a larger one to meet code and get a proper grip on a durable jacket.
• A small tilt or aim adjustment would be handy. As-is, it’s fixed-angle; I ended up shimming the front slightly in one spot to get the airflow where I wanted it.
• A two-speed fan could improve versatility—low for quiet freeze protection, high for quicker warm-up. Not a necessity, but it would round out the feature set.

Pros

• Solid heat for a 3.3 kW class unit; clean, fume-free operation
• Recessed controls and fault indicator inspire confidence
• Dual-supported coils reduce transport noise and wear
• Oversized, genuinely useful handle; stable footprint
• Wide thermostat range, suitable for freeze protection

Cons

• May ship without a cord; strain relief opening is tight for 12/3 cords
• Requires a dedicated 240V/20A circuit (not plug-and-play for many garages)
• Limited output for large, poorly insulated spaces
• Only a 1-year limited warranty

Recommendation

I recommend the DeWalt 3.3kW heater for small to medium, reasonably insulated workshops and garages where 240V/20A power is available and clean, unattended-capable electric heat is the priority. It’s well-built, straightforward to use, and delivers exactly what its specs promise: steady, focused warmth and reliable temperature hold. Just budget for a proper cord/plug and a compliant strain relief during setup, and calibrate expectations—this is a disciplined, 3.3 kW worker, not a 5–10 kW space roaster. If you need to take the edge off the cold and keep a work zone comfortable without fumes or flames, it’s a smart, durable choice. If you’re aiming to quickly heat a large, drafty shop, step up in wattage or consider supplemental insulation before you blame the heater.