Finnleo Designer SL2 8.0 kW (208V, 3-Phase) Sauna Heater

The Finnleo Designer SL2 8.0 kW in 208V, 3-phase is the largest and most powerful configuration in the Designer SL2 lineup, purpose-built for commercial installations, large custom home saunas, and spaces where three-phase power is already available. Wall-mounted to preserve bench and floor space, this heater holds a generous bed of sauna rocks in direct contact with the heating elements, delivering the fast heat-up, even temperature distribution, and authentic dry heat and steam that define genuine Finnish sauna bathing.

Key Features

• 8.0 kW output sized for saunas from approximately 300 to 425 cubic feet
• 208V, 3-phase electrical configuration for commercial and large residential installations
• Space-saving wall-mounted design that keeps the heater off the bench and out of bather space
• Rocks included, arranged in direct contact with the heating elements for authentic steam and heat
• Compatible with the SaunaLogic2 control system, available Wi-Fi or non-Wi-Fi
• Optional BioWater Technique tank compatibility for enhanced humidity control
• Requires a contactor (CB) box due to the higher amperage draw of the 8.0 kW three-phase configuration
• Available as Heater Only or bundled with a SaunaLogic2 control package

Construction & Build Quality

Like every heater in the Finnleo line, the Designer SL2 8.0 kW is manufactured by Sauna360 in Cokato, Minnesota, using Finnish sauna heating engineering and design standards. The heater housing is built from durable steel construction designed to withstand the sustained high heat of daily and commercial-grade sauna use. Every unit is safety-tested and certified for use in North America, meeting the electrical and thermal safety standards required for both residential and commercial sauna installations.

Rocks & Heating Elements

The Designer SL2 8.0 kW ships with sauna rocks included. The rocks sit in direct contact with the heating elements rather than being enclosed away from them, which allows for faster heat transfer, more even heat distribution throughout the sauna room, and better steam production when water is ladled onto the rocks. As with all Finnleo heaters, rocks are a wear item and should be inspected periodically and replaced approximately every 1 to 3 years depending on frequency of use and water quality, to maintain optimal heating performance.

SaunaLogic2 Control Compatibility

The Designer SL2 8.0 kW pairs with the SaunaLogic2 control system, available in Wi-Fi enabled and non-Wi-Fi versions. The SaunaLogic2 Wi-Fi control allows users to power on the heater, set and monitor temperature, and schedule sauna sessions remotely through a mobile app, in addition to on-unit touchscreen controls. The SaunaLogic2 ecosystem is also designed to integrate lighting and audio, allowing the heater, sauna lighting, and a Bluetooth-compatible soundbar to be managed from a single connected system for a more complete sauna experience.

Contactor (CB) Box Requirement

Because the 8.0 kW three-phase configuration draws higher amperage than the SL2 control alone is rated to switch directly, this model requires a contactor box (CB box) as part of the installation. The CB box is included in the bundled SaunaLogic2 package options for this heater and handles the higher-current switching required to safely operate the 8.0 kW element bank from the SaunaLogic2 control.

Optional BioWater Technique Tank

The Designer SL2 8.0 kW is compatible with the optional BioWater Technique tank, available as an add-on. The BioWater tank works alongside the heater to add controlled humidity to the sauna, giving bathers the option of a more traditional dry Finnish sauna heat or a softer, more humid heat, depending on preference.

What's Included

• Finnleo Designer SL2 8.0 kW, 208V 3-phase wall-mounted sauna heater
• Sauna rocks
• Choice of Heater Only, or a bundled package with the SaunaLogic2 control (Wi-Fi or non-Wi-Fi)
• Required contactor (CB) box, included with bundled SaunaLogic2 packages for this three-phase configuration
• Manufacturer installation and wiring instructions
• Full factory warranty coverage

Installation Notes

This heater requires a 208V, 3-phase electrical supply and should be installed by a licensed electrician in accordance with local electrical codes and Finnleo's installation specifications. Proper room sizing, ventilation, and clearance to combustible materials must be observed per the manufacturer's guidelines to ensure safe and efficient operation.

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 is safety-tested and listed for North America, and the SaunaLogic2 ecosystem ties your heater, lighting, and audio into one app-controlled experience. We are an authorized dealer offering full factory warranty, expert sizing help, and support before and after your purchase. Have a question about fit, voltage, or lead time? Reach out and a sauna specialist will help you spec it correctly the first time.