Finnleo Designer B 8.0 kW (208V 3PH) Sauna Heater

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

The Finnleo Designer-B 8.0 kW sauna heater delivers the same deep, even, radiant heat found across the entire Designer line — with one defining difference: the controls are built directly into the front of the heater. There's no wall-mounted control panel to purchase, wire, or find space for. A built-in 60-minute timer with a 9-hour delayed start lets you schedule your sauna to be hot and ready the moment you walk in, making the Designer-B 8.0 kW an ideal choice for larger home saunas, gyms, spas, and commercial installations where a separate remote control isn't wanted or practical. This 208V, 3-phase version is engineered for commercial and light-commercial electrical services common in health clubs, hotels, and multi-family properties, drawing lower per-leg amperage than an equivalent single-phase unit while delivering the same fast heat-up and strong recovery in rooms up to 425 cubic feet.

Key Features

• Wall-mounted electric sauna heater with integrated front-panel controls — no separate wall control required
• Built-in 60-minute timer with 9-hour delayed start for scheduled heating
• Built-in high-limit safety control with manual reset button
• Three 2670W heating elements deliver a combined 8.0 kW output for fast heat-up and strong recovery in larger rooms
• 208V, 3-phase configuration draws lower per-leg amperage than single-phase, well suited to commercial panels
• Sized for sauna rooms from 250 up to 425 cubic feet
• Rock capacity sufficient to fully surround and cover all three elements for authentic, even heat radiation and soft löyly
• Available in 4.5, 6.0, and 8.0 kW versions, and in single-phase (240V/208V) or three-phase configurations
• Compact wall-mounted design that maximizes usable floor and bench space
• Rocks included with every heater
• Compatible with Finnleo's SaunaLogic2® ecosystem for lighting and audio integration in the same room

Room Sizing & Heater Specifications

• Model: Designer 8.0B, 3-Phase (Product Number 1712-80-17-3)
• Output: 8.0 kW total, from three 2670W heating elements
• Minimum room size: 31 sq. ft. floor area with 74" wall height
• Maximum room size: 425 cubic feet with 96" wall height (250 cubic feet at 74" wall height for minimum-side rooms)
• Heater dimensions: 16-1/2"W x 11"D x 23"H, wall-mounted
• Rocks included — heater must never be operated without the rock chamber properly filled and the rock guard in place

Electrical Specifications

• 208V, three-phase: 22.2 amps — requires minimum 10 AWG-3 conductor with ground (10-3 W/G) copper supply wire
• 240V, three-phase: 19.2 amps — requires minimum 10 AWG-3 conductor with ground (10-3 W/G) copper supply wire
• 240V, single-phase: 33.3 amps — requires minimum 8 AWG-2 conductor with ground (8-2 W/G) copper supply wire
• 208V, single-phase: 38.5 amps — requires minimum 8 AWG-2 conductor with ground (8-2 W/G) copper supply wire
• Use only copper supply wire rated for a minimum of 90°C, sized per the heater specification chart
• Heater and control must be grounded per the National Electrical Code (NEC) to prevent electrical shock in the event of a unit failure
• Electrical installation must be performed by a licensed electrician in accordance with the National Electrical Code and local regulations
• Contactor (if used in the circuit) must carry a minimum 250,000-cycle endurance rating
• No electrical outlets or receptacles may be installed inside the sauna room

Installation & Safety Requirements

• Minimum ceiling clearance above the heater: 44"
• Minimum clearance from heater to wooden surfaces (benches, side walls, heater fence, etc.): 2 inches; wall-mounting brackets are supplied to maintain proper clearance from the wall behind the heater
• A wooden heater guard rail or fence is required around the heater to prevent bathers from accidentally contacting hot surfaces
• Do not locate benches directly over the heater
• Sauna door must open outward and must never have a permanent locking or latch mechanism; acceptable door fittings include magnetic catches, friction catches, and spring- or gravity-loaded closures
• No shower may be installed inside a sauna room
• Required CAUTION and WARNING placards (included in the installation envelope) must be mounted per Finnleo's instructions — the CAUTION placard on the interior wall directly above the heater, and the WARNING placard on or alongside the exterior of the sauna door at eye level
• Minimum wall insulation of R-12 in 16" on-center 2x4 stud walls; recommended minimum flooring thickness of 5/8"
• Light fixtures get very hot during operation and must be positioned away from potential burn contact
• Never apply wood stain, sealant, or preservative to the interior of the sauna room

Ventilation

• Sauna air should be exchanged approximately 6 times per hour
• Fresh air inlet vent should be located in the sauna wall directly below the heater
• Air outlet must be positioned lower than the upper bench, as far from the heater as possible, and roughly 2 feet higher than the fresh air inlet
• Ventilation openings should meet UL Specification 875; minimum vent size (V, in square inches) is calculated from room floor area (R, in square feet): for R < 31 sq ft, V ≥ 9.3 sq in; for R ≥ 31 sq ft, V ≥ 0.3 × R

Operation & Rock Loading

• Set the desired bathing temperature using the built-in thermostat dial: clockwise raises temperature, counter-clockwise lowers it
• To start heating immediately, turn the timer dial clockwise past "OFF to 1" then back counter-clockwise until it clicks into the one-hour operating zone
• To delay the start, turn the timer dial into the "1 to 9" zone — the heater will automatically switch on once the selected delay period elapses
• Load rocks in stages: place smaller rocks first around the outer perimeter of the heating chamber, then completely fill all four sections (front, the two center sections between elements, and back)
• Use smaller, tightly packed rocks in the outer sections; place rocks loosely in the two center sections to avoid restricting airflow
• Ensure rocks fully cover all elements, with a loose covering of 2" to 3" above the tops of the elements
• Discard any rocks smaller than 2" as they break down and reduce airflow through the heater
• Never pour chlorinated pool or spa water onto the heater or rocks — corrosion damage may result
• Ladle only about ½ cup of water onto the rocks at a time to create löyly, and stay clear of the rising steam

What's Included

• Finnleo Designer-B 8.0 kW, 3-phase sauna heater with integrated front-panel timer and thermostat controls
• Full complement of sauna rocks
• Wall-mounting brackets
• Built-in high-limit safety control with reset button
• CAUTION and WARNING placards for required room mounting
• Complete installation and operating instructions

Maintenance

• Inspect the sauna room at the end of each day to confirm the control and heater are switched off
• Wipe down the heater occasionally with a damp cloth to remove lint and dust
• Remove rocks once a year for cleaning, and replace any small or crumbled rocks
• Keep the sauna clean and odor-free; use towels or mats on benches and floor, since perspiration otherwise penetrates untreated softwood
• Clean stains with soap or detergent in warm water using a scrub brush; sand badly soiled surfaces as needed
• Air out the sauna regularly with the door and vents open when not in use, and wash the room down at least weekly under daily use
• Remove, scrub, and dry duckboard flooring separately, and inspect benches and supporting structure annually for dry rot, age-related wear, or damage

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.