304 Gallons. Self-Cleaning Stove. 50% Less Wood. The Natural-Finish Wood-Fired Hot Tub Engineered for Efficiency.
The SaunaLife Soak-Series Model S4N is the natural Thermo-Spruce exterior version of SaunaLife's efficiency-focused wood-burning hot tub — combining quality, performance, and luxury in a 79-inch diameter tub that comfortably accommodates up to 6 people. At the heart of the S4N is a unique self-cleaning stove that reduces wood consumption by up to 50% compared to traditional wood-fired tubs, while its advanced water circulation design heats the full 304-gallon capacity from 40°F to 95°F in just 1.5 to 2 hours — engineered in Northern Europe for genuinely rapid, efficient performance. The ergonomically shaped, dark grey contoured fiberglass tub interior is easy to clean and comfortable against the body, while the exterior is built from thermally enhanced Thermo-Spruce — lasting up to twice as long as cedar with superior thermal resistance to retain heat, finished in its natural golden tone rather than the painted black of the standard S4. The 304 stainless steel wood-burning heater with dual heat compartments drives this efficiency, topped with a polished stainless steel chimney and protective cap. No electrical connection is required — the S4N arrives fully assembled with matching Thermo-Spruce steps, an extra-thick steel-reinforced foam cover with dark grey marine-grade vinyl exterior that folds for storage, and an integrated drainage tap. For gatherings with family and friends, off-grid relaxation, or a natural wood aesthetic that blends into garden and timber landscapes, the S4N delivers quick, effortless luxury.
Key Specifications
- Series: Soak-Series
- Model: S4N (Natural Thermo-Spruce exterior)
- Type: Wood-burning outdoor hot tub — no electricity required
- Capacity: Up to 6 bathers
- Water Capacity: 304 gallons
- Exterior Dimensions: 79 in diameter × 37 in high
- Interior Dimensions: 71 in diameter × 33 in deep
- Tub Surround: 1.65 in thick natural Thermo-Spruce
- Interior Lining: Thick, dark grey contoured fiberglass — ergonomically shaped, easy to clean
- Heater: 304 stainless steel wood-burning heater — dual heat compartments, self-cleaning stove design
- Wood Consumption: Reduced by up to 50% versus traditional wood-fired tubs
- Heat-Up Performance: 304 gallons from 40°F to 95°F in 1.5–2 hours
- Maximum Temperature: 106°F
- Chimney: Polished stainless steel with protective cap
- Stove Dimensions: 19.8 in L × 11.8 in W × 13.1 in H
- Chimney Dimensions: 95 in H × 4.7 in diameter
- Maximum Wood Length: 16 in
- Access: Matching Thermo-Spruce wood steps
- Cover: Extra-thick steel-reinforced foam, folding design, dark grey marine-grade vinyl exterior
- Drainage: Integrated drainage tap
- Product Weight (filled): 3,064 lbs
- Shipping Dimensions: 91 in L × 46 in W × 87 in H
- Shipping Weight: 595 lbs
- Assembly: Fully assembled — ready to fill and fire
- Electrical Requirement: None — fully off-grid compatible
- Use: Outdoor
- Warranty: SaunaLife Limited Lifetime Warranty (residential use)
- Origin: Designed by SaunaLife, handcrafted in Northern Europe
Who This Is For
The S4N is the right choice for buyers who want everything the S4 offers — 304-gallon capacity, self-cleaning efficient stove, fully assembled delivery, zero electrical requirements — in a natural Thermo-Spruce finish that complements gardens, timber decks, and natural landscapes rather than the S4's painted black exterior. It suits families and small groups of up to 6, off-grid and rural property owners, and buyers who specifically want the documented 50% wood-consumption reduction and 1.5-to-2-hour heat-up performance from 40°F to 95°F that the self-cleaning stove design delivers.
Frequently Asked Questions
Q: What is the only difference between the S4N and the S4?
A: Exterior finish. The S4N has a natural Thermo-Spruce finish — golden, organic, complements garden and timber settings. The S4 is painted black for a modern, high-contrast look. Every other specification is identical: 304-gallon capacity, 79-inch diameter, 304 stainless steel dual-compartment heater, self-cleaning stove design, fully assembled delivery, and matching included accessories.
Q: How does the self-cleaning stove reduce wood consumption by 50%?
A: The dual heat compartment design captures and recirculates heat more efficiently than traditional single-chamber wood stoves, extracting more usable heat energy per unit of wood burned. This translates directly into the documented heat-up performance: 304 gallons heated from 40°F to 95°F in just 1.5 to 2 hours, using roughly half the wood that a traditional wood-fired tub would require for the same temperature rise.
Q: Does it require any electrical connection?
A: None. The S4N is entirely wood-fired, with water circulation driven by natural convection through the dual-compartment stove. No pumps, motors, or electrical connections are needed — fully compatible with off-grid properties and locations without electrical infrastructure access.
Q: What is included with the S4N?
A: The S4N arrives fully assembled and includes matching Thermo-Spruce steps for access, an extra-thick steel-reinforced foam cover with dark grey marine-grade vinyl exterior (folds for easy removal and storage), integrated drainage with a tap, a polished stainless steel chimney, and a chimney cap.
Q: What foundation does the S4N require?
A: A flat, level, stable surface capable of supporting the tub's filled weight of approximately 3,064 lbs. Concrete pads, compacted gravel, or reinforced decking are appropriate. The surface must be completely level for proper stove operation and even weight distribution.
Q: Can the S4N be paired with a sauna or shower for a complete wellness setup?
A: Yes — the S4N pairs naturally with any SaunaLife sauna or barrel sauna for a hot-to-hot or contrast circuit, and with the RAIN-Series R3 outdoor shower for rinsing before and after soaks. Its natural Thermo-Spruce finish coordinates particularly well with natural-finish saunas like the SaunaLife G2, S6N, or ERGO-Series models for a cohesive backyard wellness aesthetic.
