Finnleo Magma Sauna Heater

Finnleo Magma Sauna Heater Series

The Finnleo Magma is Finnleo's commercial-grade, floor-standing electric sauna heater line, engineered for large traditional sauna rooms that demand serious, sustained heat and generous löyly (steam). Manufactured by Sauna360 in Cokato, Minnesota, the Magma series is offered in three power outputs and two three-phase voltage configurations to match nearly any large-format home, spa, gym, or commercial sauna installation: 21.0 kW (208V 3PH or 480V 3PH), 24.0 kW (208V 3PH or 480V 3PH), and 28.8 kW (208V 3PH or 480V 3PH). Every Magma heater holds a substantial bed of sauna rocks in direct contact with high-output heating elements, delivering deep, penetrating heat and rich steam even in oversized rooms that a standard wall-mounted heater simply can't handle.

Key Features

• Commercial floor-standing heater with approximately 198 lb rock capacity across all models
• Available in three outputs — 21.0 kW, 24.0 kW, and 28.8 kW — each offered in 208V or 480V three-phase
• Sized for sauna rooms from approximately 720 to 2,000 cubic feet, depending on kW selected
• Rugged stainless-steel outer shroud built for continuous high-heat, high-steam duty cycles
• Pairs with Finnleo's commercial SaunaLogic2 (SL2-C) control system
• Remote control installation — mount the control panel outside the sauna room to lock in preset limits
• Door switch (interlock) compatibility for automatic shut-off and energy management
• Programmable temperature and run-time settings for predictable, code-compliant operation
• Sauna stones included on every configuration
• Available as Heater Only or as a complete bundled package with SL2-C control and required contactor box(es)
• ETL listed and safety-tested for the North American market

Power & Sizing Options

Choosing the right Magma output and voltage comes down to room volume and the electrical service available at the installation site:

• 21.0 kW (208V or 480V, 3PH): The entry point into the Magma series, sized for sauna rooms from roughly 720 to 1,270 cubic feet. The right fit for large home saunas, boutique spas, gyms, and small commercial rooms that have outgrown a wall-mounted heater.
• 24.0 kW (208V or 480V, 3PH): A mid-tier output covering approximately 1,150 to 1,550 cubic feet, suited to larger commercial sauna rooms and higher-traffic spa or fitness-club installations that need faster heat recovery between sessions.
• 28.8 kW (208V or 480V, 3PH): Finnleo's highest-output electric heater, built for the largest traditional sauna rooms — approximately 1,550 to 2,000 cubic feet. Designed for demanding commercial environments such as hotels, health clubs, and multi-bather public saunas where consistent, powerful heat is essential.

All six configurations share the same floor-standing housing, rock capacity, and SL2-C control compatibility — the difference lies strictly in heat output, room-volume rating, and voltage/phase-specific electrical requirements.

Construction & Build Quality

Every Magma heater is built as a floor-standing unit rather than the compact wall-mounted heaters found in Finnleo's residential Designer SL2 line. Its rugged stainless-steel outer shroud is engineered to withstand the demanding combination of extreme heat, moisture, and steam found in heavy-use traditional saunas, ensuring long-term durability in both residential and commercial settings. Internally, the heater is engineered for reliable, high-output performance, and larger rooms may call for multi-heater configurations to achieve even heat distribution. All Finnleo Magma heaters are ETL listed, meeting safety standards for installation in the United States and Canada.

Rocks & Heating Performance

Every Magma heater — regardless of kW rating or voltage — holds approximately 198 lbs of high-quality sauna stones, giving the series substantial thermal mass. This large rock bed absorbs and radiates heat evenly throughout even the largest sauna volumes, minimizing cold spots, and produces a soft, plentiful löyly when water is ladled onto the hot stones — the hallmark of true Finnish sauna bathing. For continued performance, stones should be inspected and repositioned roughly once a year to preserve airflow, with full replacement recommended every 2–5 years depending on usage intensity.

SaunaLogic2 (SL2-C) Control System

Every Magma heater is matched with Finnleo's SaunaLogic2 SL2-C control, a commercial-grade control package built specifically for high-use and multi-heater sauna environments. Its features include:

• Sleek digital touchscreen interface for temperature display and adjustment
• Remote installation capability — the control unit can be mounted outside the sauna room so bathers cannot alter preset temperature or run-time limits, ensuring consistent operation in commercial or shared settings
• Programmable run time and temperature settings for predictable, energy-conscious operation
• Door switch integration — the heater automatically shuts off if the sauna door is opened and left open, supporting both safety and energy efficiency
• Optional external, low-voltage on/off switch for added convenience

Electrical & Contactor Box Requirements

Because the Magma series draws significant three-phase power, every configuration requires the SL2-C control paired with the correct contactor box(es) to safely bridge the low-voltage control with the heater's high-power circuit:

• 208V, 3-phase models (21.0, 24.0, and 28.8 kW): Require both a CB 17-3 and a CB 18-3 contactor box working together to manage the higher amperage draw of 208V three-phase service.
• 480V, 3-phase models (21.0, 24.0, and 28.8 kW): Require a single CB 17-3 contactor box, thanks to the lower amperage draw at 480V — a configuration often preferred in commercial and industrial buildings where 480V service is already standard.

A separate 120V supply is also required for the SL2-C control box itself on all configurations. Given the power levels involved, installation must be performed by a qualified, licensed electrician in accordance with the heater's installation manual, ensuring correct breaker sizing, wire gauge, and contactor wiring for a safe, code-compliant setup.

What's Included

• Finnleo Magma heater unit (21.0, 24.0, or 28.8 kW, in 208V or 480V 3-phase, per selection)
• Approximately 198 lbs of sauna stones
• Temperature sensor
• SaunaLogic2 (SL2-C) control unit (on bundled packages)
• Required contactor box(es): CB 17-3 and CB 18-3 for 208V models, or CB 17-3 alone for 480V models
• Installation and operation manuals
• Factory warranty

Choose Heater Only if you already have a compatible SL2-C control and contactor box(es), or select a complete package that bundles the control and the correct contactor box(es) for your specific voltage and phase configuration. Rocks are included on every option.

Installation & Usage Notes

The Magma is a floor-standing heater intended for large traditional (non-infrared) sauna rooms and is not designed or sized for small residential saunas — doing so would result in inefficient, overly rapid heating. Proper room construction and ventilation are essential to safe, effective operation, and room cubic footage should always be confirmed against the selected kW rating before purchase. Routine maintenance is minimal: reposition sauna stones roughly once a year to preserve airflow, replace stones every 2–5 years as needed, and wipe down the stainless-steel exterior with a damp cloth using only clean water on the heater — never pool water or chlorinated water.

Why Buy Finnleo From Us

Finnleo, built by Sauna360 in Cokato, Minnesota, is one of the most trusted names in authentic Finnish sauna. Every heater in the Magma series is safety-tested and ETL listed for North America, and the SaunaLogic2 ecosystem ties your heater, lighting, and controls into one cohesive, app-ready experience. We are an authorized Finnleo dealer offering full factory warranty coverage (1-year commercial / 5-year residential), expert sizing help, and support before and after your purchase. Have a question about fit, voltage, contactor boxes, or lead time? Reach out and a sauna specialist will help you spec the right Magma configuration the first time.