The main difference is 120V heaters plug into a standard outlet at around 1500W, while 240V heaters typically need a dedicated circuit and deliver 2000W to 4000W or more.
One decision separates a heater you carry home and plug in from one that requires an electrician and a dedicated breaker: the voltage. Choosing the wrong one wastes money on a unit that can’t run on the circuit you already have, and the mismatch is more than an inconvenience — manufacturer manuals state a heater’s voltage must match the building’s supply power, since feeding a 240V unit a 120V line (or the reverse) can cause improper operation or damage.
This guide covers what each voltage actually delivers, how installation differs, and which one fits your patio. If you’re leaning toward the simpler plug-in option, our tested roundup of 120V patio heaters covers the standout models worth buying.
How Much Heat Does Each Voltage Deliver?
The voltage itself doesn’t create heat — wattage does, and higher voltage lets a circuit carry more wattage safely. A 120V heater running on a standard 15-amp household circuit tops out around 1500W, which is why nearly all plug-in models land there. A 240V unit can pull far more current on a higher-voltage line, and models commonly range from about 2000W to 4000W or higher. For example, the Bromic Tungsten Smart Heat 4000W Electric Patio Heater (BH0420032) is specified for 220V–240V and draws about 16.6 amps.
The practical takeaway: 120V heaters warm a smaller, closer seating zone, while 240V heaters cover larger patios or handle colder conditions, because they simply move more power into the same element.
What Does Installation Require for Each?
This is where the two diverge most. A 120V heater usually plugs into a standard grounded outlet with no wiring, so it’s a same-day setup. A 240V heater typically isn’t a plug-in product at all — most require a dedicated circuit and hardwiring, and manuals repeatedly specify that a licensed electrician make the connections per local and NEC code.
The specifics from manufacturer documentation:
- 220–240V plug-in units must connect only to a grounded 220–240V, 50–60Hz, 15A outlet, installed in an open area with proper clearances.
- Hardwired 240V units should connect to a dedicated circuit — Infratech documentation, for instance, calls for a 240V, 10A dedicated circuit, power disconnected at the breaker before wiring, and strict adherence to the wiring diagram.
- Fixed-installation units — like the Bromic 220–240V line — are built for permanent mounting, with electrical work done by a qualified electrician.
Installation isn’t only about wiring. Manuals set minimum distances from walls, ceilings, and combustible materials, plus specific mounting heights, and those limits vary by model. At least one manual requires mounting the heater outdoors or in a large open area away from obstructions and flammable objects.
| Factor | 120V Heater | 240V Heater |
|---|---|---|
| Typical wattage | Around 1500W | 2000W–4000W+ |
| Power source | Standard grounded outlet | Dedicated higher-voltage circuit |
| Installation | Often plug-in, DIY-friendly | Usually hardwired by an electrician |
| Best for | Small patios, close seating | Large patios, colder conditions |
| Coverage | Smaller, focused zone | Larger area |
| Setup cost | Low | Higher (wiring, labor) |
| Portability | Often portable | Typically fixed in place |
Which Voltage Is Right for Your Patio?
Match the heater to the circuit you actually have. If all you have is standard 120V power, a 120V heater is the honest answer — a 240V unit can’t run on that line without new wiring. Buy a 240V heater only when you’re prepared to install a dedicated circuit, or when the space already has one.
One more wrinkle: not every heater family is single-voltage. The Schwank eSchwank ES/ESD Series lists 120V, 208V, 240V, 277V, and 480V configurations, showing some commercial lines sell in multiple electrical setups. Always verify the exact voltage on the model’s spec sheet before buying.
The most common mistakes to avoid:
- Buying a 240V heater for a space that only has 120V power available.
- Assuming every electric patio heater is plug-in and needs no electrician.
- Ignoring model-specific clearance, mounting height, and grounding requirements.
- Running a heater on a circuit that doesn’t meet its amperage or dedicated-circuit specs.
If your space suits the plug-in route, the fastest path is confirming your outlet’s limits, then picking a 1500W model sized to your seating area.
FAQs
Can I plug a 240V heater into a regular wall outlet?
No. Standard U.S. wall outlets supply 120V, so a 240V heater needs a dedicated higher-voltage circuit. Most 240V models are hardwired rather than plug-in, and manufacturer manuals specify that a licensed electrician handle the connection per local code.
Do I need an electrician to install a 240V patio heater?
Almost always, yes. Manuals for 240V units repeatedly state that electrical connections must be made by a licensed or qualified electrician, following local and NEC requirements with proper grounding. A 120V plug-in model, by contrast, typically needs no wiring work at all.
Is a 120V heater strong enough for a covered patio?
For a small patio or a close seating zone, a 1500W 120V heater can be enough. It delivers less total heat than a 240V unit, so for larger areas or colder conditions, a higher-wattage 240V model is the better match — provided your space supports the circuit.
References & Sources
- Schwank. “eSchwank Electric Outdoor Heaters.” Shows a heater family offered in multiple voltages: 120V, 208V, 240V, 277V, and 480V.
- Bromic Heating. “Cobalt Electric Heater Spec Sheet.” Confirms 220V–240V fixed-installation specs and qualified-electrician wiring requirements.
- Berner. “Luminous Patio Heater Installation Instructions.” Details voltage-matching, clearances, and dedicated-circuit requirements.
