The best part of my day!

I use my Infrared Sauna every evening, and it’s honestly the calmest part of my day.

Sara L.

Verified Buyer

Hot Tub - SaunaLife S4B

★★★★★
330 Reviews
Fits 6 People
Units Sold This Month

Relax in soothing warmth that melts away stress and muscle tension. The heat boosts circulation, supports metabolism, and promotes gentle detoxification. Enjoy clearer skin and renewed energy with every soak.

Ready for your hot tub party  

The Model S4B wood-fired hot tub arrives completely assembled and is easy to set up. Its ergonomically shaped fiberglass tub is a comfortable place for up to 6 people. The interior surface is easy to clean, and the exterior is crafted from thermally enhanced spruce for superior weather resistance and durability. 

Engineered for efficiency and performance 

Engineered and crafted in the Northers Europe, this super-efficient hot tub heats in 1/3 of the time as traditional wood-fired hot tubs. No electrical connection is required. At the heart of the Model S4 is its ingenious self-cleaning corrugated stove with a secondary chamber that transfers heat from the smoke – reducing wood consumption up to 50% compared with other hot tubs. Brilliantly, the air between the fiberglass lining and the wood exterior is super-heated to accelerate the heating process. The stove is cleverly engineered to draw cooler water through a lower channel and redistribute it though an upper channel to equalize the temperature.  

Start enjoying sooner 

This incredibly efficient wood stove will heat 304 gallons of water from 40°F (5°C) to 95°F (35°C) in 1.5 to 2 hours – the fastest-heating wood-burning hot tub available.  

Relax with friends and family the luxury of your Model S4 backyard wood-burning hot tub from SaunaLife. 

Model

Model S4B

Material

Thermo-Spruce

Interior Dimensions

71" Diameter x 33"D

Exterior Dimensons

79" Diameter x 37"H

Water Capacity

304 Gallons

Product Weight when filled

3064 lbs

Stove Dimensions

19.8"L x 11.8"W x 13.1"H

Chimney Dimensions

95"H x 4.7" Diameter

Maximum Wood Length

16"

Maximum Temperature

106F

Shipping Dimensions

91"L x 46"W x 87"H

Shipping Weight

595 lbs

Improves circulation & relief

Supports detox & metabolism

Enhances skin & recovery

Starting at
/Month or
Regular price $5,990 Sale price $4,193
Fits 6 People
0% Interest for 24 Months | Select at Checkout
icon In Stock, Ready to Ship by
icon Description

Description

Relax in soothing warmth that melts away stress and muscle tension. The heat boosts circulation, supports metabolism, and promotes gentle detoxification. Enjoy clearer skin and renewed energy with every soak.

Ready for your hot tub party  

The Model S4B wood-fired hot tub arrives completely assembled and is easy to set up. Its ergonomically shaped fiberglass tub is a comfortable place for up to 6 people. The interior surface is easy to clean, and the exterior is crafted from thermally enhanced spruce for superior weather resistance and durability. 

Engineered for efficiency and performance 

Engineered and crafted in the Northers Europe, this super-efficient hot tub heats in 1/3 of the time as traditional wood-fired hot tubs. No electrical connection is required. At the heart of the Model S4 is its ingenious self-cleaning corrugated stove with a secondary chamber that transfers heat from the smoke – reducing wood consumption up to 50% compared with other hot tubs. Brilliantly, the air between the fiberglass lining and the wood exterior is super-heated to accelerate the heating process. The stove is cleverly engineered to draw cooler water through a lower channel and redistribute it though an upper channel to equalize the temperature.  

Start enjoying sooner 

This incredibly efficient wood stove will heat 304 gallons of water from 40°F (5°C) to 95°F (35°C) in 1.5 to 2 hours – the fastest-heating wood-burning hot tub available.  

Relax with friends and family the luxury of your Model S4 backyard wood-burning hot tub from SaunaLife. 

icon Features

Features

Model S4B Outdoor Wood-Burning Hot Tub   

  • Thermo-Spruce materials (lasts up to 2X longer than Cedar)  
  • Luxury outdoor wood-burning hot tub 
  • Designed for outdoor ergonomic hot tub bathing experiences 
  • Arrives fully assembled and no electricity required (eco-friendly) 
  • Spacious interior holds over 304 gallons of pure water bathing pleasure 
  • Thick dark grey contoured fiberglass lining provides enhanced bather comfort 
  • Stainless steel wood-burning heater utilizes dual heat compartments for unmatched efficiency   
  • Rapid response heat-up time prepares water to ideal temperatures in under 2-hours 
  • Wood-burning heater constructed of 304 stainless steel 
  • Polished stainless steel chimney with protection 
  • Durable Thermo-Spruce tub surround (1.65” thick), painted black  
  • Superior thermal resistance (R-value) to retain heat  
  • Matching Thermo-Spruce wood steps for easy access 
  • Extra thick steel reinforced foam cover, folds for ease of removal and storage 
  • Dark grey marine grade vinyl cover exterior 
  • Integrated hot tub drainage tap 
  • Up to 6 bathers 
  • Exterior dimensions – 79" diameter and 37” high  
  • Interior dimensions – 71" diameter and 33” deep 
  • Designed by SaunaLife and handcrafted in Northern Europe 

Thermo-Spruce Material Advantages 

  • Lasts up to 2X longer than Cedar 
  • Superior thermal resistance (R-value) 
  • Eco-friendly 
  • Ideal for water use (stable)  
What's Included In It:

Model S4B Outdoor Wood-Burning Hot Tub  

  • Fully assembled hot tub 
  • Steps 
  • Insulated cover  
  • Drainage with tap 
  • Polished stainless steel chimney 
  • Chimney cap 
icon Specifications

Specifications

Model

Model S4B

Material

Thermo-Spruce

Interior Dimensions

71" Diameter x 33"D

Exterior Dimensons

79" Diameter x 37"H

Water Capacity

304 Gallons

Product Weight when filled

3064 lbs

Stove Dimensions

19.8"L x 11.8"W x 13.1"H

Chimney Dimensions

95"H x 4.7" Diameter

Maximum Wood Length

16"

Maximum Temperature

106F

Shipping Dimensions

91"L x 46"W x 87"H

Shipping Weight

595 lbs

icon Technical

Used by Celebrities in the Fitness Space 🔥

Kim Kardashian

Kim Kardashian

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Busy Philipps

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Zac Efron

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Lady Gaga

Hot Tub - SaunaLife S4B

Hot Tub - SaunaLife S4B

Starting at
/Month or $4,193

LUXURY LIVING, EVERDAY WELLNESS

APPROVED BY EXPERTS

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EXPERIENCE THE TRANSFORMATION

Top Benefits of Hot Tub Use

Our Success Stories

What Our Customers Say

Jason M.

Stars

"The canopy design is beautiful and the heat is just right. It’s become my favorite home ritual.”

12/09/25 Verified Sauna Buyer

Megan W

Stars

“Setup was easier than I thought. Now my mornings start with calm and clarity.”

18/09/24 Verified Sauna Buyer

Robert H.

Stars

“Serious luxury that provides serious relaxation. My bloodstream thanks me every time.”

12/09/23 Verified Sauna Buyer

Sarah M.

Stars

“Shipping was on time, the quality exceeded my expectations, and the support team genuinely cared.”

18/5/24 Verified Sauna Buyer

Laura G.

Stars

“Feels like we brought a high-end spa home. Best investment in our wellness yet.”

12/7/25 Verified Sauna Buyer

Denise K.

Stars

“Sturdy, stunning, and spacious—exactly what we needed for evenings with friends.”

16/4/25 Verified Sauna Buyer

Emily R.

Stars

"I can’t believe how relaxing this sauna is! It feels like having a spa right at home. The quality is amazing and it heats up quickly."

6/12/24 Verified Sauna Buyer

Michael T.

Stars

"Bought one for my backyard and it’s the best decision ever. After work, I sit in for 20 minutes and all my stress just melts away."

5/8/25 Verified Sauna Buyer

David K.

Stars

"This sauna has changed my evenings. I use it with my wife almost every night—it’s cozy, private, and feels premium."

4/7/24 Verified Sauna Buyer

Mark J.

Stars

"I use it after gym sessions and it’s perfect for muscle recovery. Plus, it adds a real luxury feel to my home."

17/11/24 Verified Sauna Buyer
Background Image

Questions?
We've Got Answers

What is the capacity and intended use of the Model S4B?

The S4B is a wood-burning hot tub built to accommodate up to 6 persons, meant for outdoor soaking, wellness, and group bathing.

What materials are used in its construction?

Its shell is made of Thermo-Spruce wood (which is more durable than untreated cedar), and the interior is lined with contoured dark gray fiberglass for comfort and easy maintenance.

Is any electrical connection required?

No, the S4B arrives fully assembled and is fully functional without any electricity; it runs purely with wood heat.

What is the water capacity and heating performance?

The tub holds over 304 gallons of water. It can heat from cold temperatures up to approximately 95 °F (35 °C) in 1.5 to 2 hours under ideal conditions.

What heating system does it use?

It uses a stainless steel wood-burning heater with dual heat compartments, a corrugated self-cleaning stove, and smoke heat-exchange design to reduce wood consumption and improve efficiency.

How is heat distribution and efficiency handled?

The design draws cooler water through a lower channel and redistributes it via an upper channel to equalize temperatures. The outer air space between fiberglass and wood is also superheated to speed heating.

What is the main advantage of the S4B’s heating system?

Its efficient wood stove design can heat more quickly and uses less wood (claimed up to 50% less wood) compared to conventional wood-fired tubs.

What kind of maintenance or setup is needed?

Since it arrives fully assembled, setup is minimal. Users should maintain the stove and chimney, and care for the wood exterior with periodic treatments (e.g. UV protective finishes) to preserve longevity.

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