SaunaLife Model S6B: Large Black Wood-Fired Hot Tub for Up to 7 People

The SaunaLife Model S6B is a 7-person wood-fired hot tub with a bold black Thermo-Spruce exterior, built for larger groups. With a 436-gallon capacity and 89-inch diameter, the S6B is the biggest tub in the SOAK Series — and it uses the same high-efficiency dual-chamber stove technology as the S4. The 304 stainless steel self-cleaning corrugated stove heats the full volume from 40°F to 95°F in approximately 2 to 2.5 hours, using up to 50% less wood than traditional wood-fired tubs. No electricity required. The black thermally modified wood finish delivers a modern, premium aesthetic, and the contoured dark grey fiberglass interior comfortably seats up to 7 bathers.

Same Efficient Stove, Bigger Tub

The S6B uses the same ingenious dual-chamber stove as the S4. The primary chamber burns the wood while the secondary chamber captures and recycles heat from the smoke — reducing wood consumption by up to 50% compared to traditional wood-fired hot tubs. The stove draws cooler water in through a lower channel and redistributes heated water through an upper channel, equalizing temperature throughout the tub. Even with 436 gallons, you're soaking in about 2 to 2.5 hours.

Room for the Whole Group

The S6B's 89-inch diameter and 436-gallon capacity give up to 7 adults plenty of room to soak comfortably — making it ideal for families, entertaining, or hospitality environments. The ergonomically contoured fiberglass interior follows the natural shape of the body, and matching black Thermo-Spruce wood stairs make entry and exit easy. An insulated marine-grade vinyl cover is included to retain heat between uses and keep debris out.

No Electricity, No Hassle

The S6B runs entirely on firewood — no electrical hookup, no wiring, no electrician. Place it on a level outdoor surface, fill it with a garden hose, light the stove, and you're soaking in about 2 hours. A built-in drainage tap makes water changes simple.

Built to Last Outdoors

The 1.65-inch thick black Thermo-Spruce exterior is thermally modified to last up to twice as long as cedar, with superior thermal resistance to retain heat. The fiberglass interior is durable, easy to clean, and designed for years of heavy use. A polished stainless steel chimney with rain cap completes the setup.

The SaunaLife Model S6B is handcrafted in Northern Europe and backed by a Limited Lifetime Warranty. Our wellness specialists are available 7 days a week to help with setup, placement, or any questions about your new hot tub.

Features

Heating & Efficiency

• 304 Stainless Steel Dual-Chamber Stove — Self-cleaning corrugated design heats 3× faster than traditional tubs
• 50% Less Wood Consumption — Secondary chamber recycles heat from smoke for maximum efficiency
• ~2–2.5 Hour Heat Time — 436 gallons from 40°F to 95°F, among the fastest wood-fired tubs available

Construction & Materials

• Black Thermo-Spruce Exterior (1.65" Thick) — Lasts up to 2× longer than cedar with superior thermal resistance
• Contoured Fiberglass Interior — Dark grey ergonomic basin for comfortable 7-person soaking
• Polished Stainless Steel Chimney — Includes rain cap for weather protection

Convenience & Setup

• Fully Pre-Assembled — Ships ready to use, no construction required
• Zero Electricity Required — 100% wood-fired, place anywhere outdoors
• Insulated Marine-Grade Cover — Steel-reinforced foam with vinyl exterior, folds for easy removal

Quality & Warranty

• Handcrafted in Northern Europe — Designed by SaunaLife and built in Estonia
• Limited Lifetime Warranty — Long-term protection on materials and craftsmanship
• Matching Black Thermo-Spruce Stairs — Included for safe, easy tub access

Specifications

Dimensions

• Exterior Diameter: 89" (226.1 cm)
• Exterior Height: 40.2" (102.1 cm)
• Interior Diameter: 80.7" (205 cm)
• Interior Height: 35.4" (89.9 cm)

Capacity

• Bathers: Up to 7 persons
• Water Capacity: 436 gallons

Heating

• Heater Type: 304 stainless steel self-cleaning corrugated wood-burning stove
• Heat Chambers: Dual (primary + secondary smoke heat recovery)
• Heat Time: 40°F to 95°F in ~2–2.5 hours
• Electricity Required: None

Construction

• Exterior Material: Black Thermo-Spruce (1.65" thick)
• Interior Material: Dark grey contoured fiberglass
• Finish: Black wood
• Chimney: Polished stainless steel with rain cap
• Cover: Steel-reinforced foam, marine-grade vinyl exterior

Weight & Shipping

• Product Weight: 551 lbs (249.9 kg)
• Shipping Weight: 728 lbs (330.2 kg)
• Shipping Dimensions: 93"W × 47.2"D × 94.5"H
• Shipping Method: Palletized LTL Freight

Certifications

• Origin: Handcrafted in Northern Europe (Estonia)
• Warranty: Limited Lifetime
• Prop 65: No

What's Included

In the Box

• SaunaLife Model S6B wood-fired hot tub (fully assembled)
• 304 stainless steel wood-burning stove (installed)
• Matching black Thermo-Spruce stairs
• Insulated marine-grade vinyl cover
• Polished stainless steel chimney
• Chimney rain cap
• Integrated drainage tap

Required for Operation (Sold Separately)

• Firewood (hardwood recommended)
• Garden hose or water source for filling
• Fire starter / kindling

Resources

• SaunaLife Model S6B Installation & Operation Manual (PDF)
• SaunaLife Limited Lifetime Warranty (PDF)