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✅ Authorized Reseller
✅ Authorized Reseller

SaunaLife Model S4 Wood-Fired Hot Tub

SKU SL-MODELS4B
Availability:
in stock, ready to be shipped
Original price $5,990.00 - Original price $5,990.00
Original price
$5,990.00
$5,990.00 - $5,990.00
Current price $5,990.00

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✓ Manufacturer Warranty Included
✓ Financing Available at Checkout
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SaunaLife Model S4 Wood-Fired Hot Tub

Experience unparalleled wood-burning hot tub luxury with the SaunaLife Model S4 Wood-Fired Hot Tub. Constructed with the best quality Thermo-Spruce materials which last up to 2X the life of Cedar, this SOAK-Series Model outdoor hot tub is designed for ergonomic bathing pleasure. It holds over 304 gallons of water and its thick, dark grey contoured fiberglass lining provides maximum comfort. The wood-burning heater is constructed of 304 stainless steel and includes a stainless steel chimney with protection for rapid heat-up response times, heating the water to ideal temperatures in under two hours.

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)  

Includes

Model S4B Outdoor Wood-Burning Hot Tub  

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

Note: Each S4 Hot Tub comes fully assembled and includes steps, a dark grey marine grade vinyl insulated cover, drainage with tap, a polished stainless steel chimney and a chimney cap.

      Specifications

      Item Model S4
      Material 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 3064lbs
      Stove Dimensions 19.8"D x 11.8"W x 13.1"H
      Chimney Dimensions 4.7"Diameter x 95"H
      Maximum Wood Length 16"
      Maximum Temperature 106F
      Shipping Dimensions 91"L x 46"W x 87"H
      Shipping Weight 595 lbs


      DIAGRAMS

      Need a visual diagram showing dimensions? View hot tub dimensons and diagrams

      Warranty

      SAUNA LIFE SAUNA LIMITED LIFETIME WARRANTY

      Sauna Life extends this Limited Warranty solely to the original retail consumer purchaser of any Sauna Life sauna purchased from one of its authorized resellers.

      LIMITED LIFETIME SAUNA WARRANTY

      Sauna Life warrants that the Sauna Life sauna shall be free from defects in workmanship under normal conditions of use and service for the lifetime of the sauna for residential applications after delivery to the original retail purchaser. This warranty is limited to making good any factory assembled component which in the judgment of Sauna Life is deemed defective in workmanship. The warranty does not cover normal material wear, natural weathering of the lumber, or installation or delivery of components and applies only to the original retail purchaser.

      WARRANTY PERFORMANCE

      For any warranty service, Sauna Life reserves the right to choose, at its option, repair of the problem or a replacement of the defective part. Sauna Life reserves the right to substitute a part or component of equivalent value, either new or factory reconditioned, and any such repair or replacement shall assume as its warranty only the remaining portion of the warranty on the original product. In the event Sauna Life chooses to repair any malfunction or defect covered by this warranty, a return authorization will be issued, and the component will be returned prepaid freight to Sauna Life for repair of the defect. Sauna Life will then ship the component back the original retail purchaser upon completion of the repair. Prior to any return, contact Sauna Life at: Sauna Life, 511 Glenn Avenue, Wheeling, Illinois 60090, telephone number: (800) 957-2862, for packaging and shipping instructions and a return authorization number. In addition, Sauna Life will require photographs of any defect and reserves the right to inspect or designate an agent to inspect any part that is claimed to be defective and covered by this warranty. Labor charges and related expenses for removal, installation, or replacement of the sauna or its components are not covered under this warranty. Normal wear and tear, cosmetic issues or changes to individual pieces of lumber due to natural aging and weathering are not covered. Sauna heaters and added components are not covered by this warranty.

      ACTS INVALIDATING WARRANTY

      This warranty is void if the Sauna Life sauna has been subject to alteration, misuse or abuse, commercial use, or if any repairs on the sauna are attempted by anyone other than an authorized representative of Sauna Life. Alteration shall include, but is not limited to, deviation from the original assembly instructions, component change, or the addition of any non-approved device or heating system, which contributes to a component or unit failure, or unsafe operating system. Use of the sauna in an application for which it is not designed will void this warranty. This includes, but is not limited to, damage caused by operation above safe sauna operating temperatures, damage caused by added components, damage to the sauna’s surface caused by harsh chemicals, damage caused by movement of the product, and damage caused by acts of God.

      DISCLAIMERS

      Except as expressly provided above, Sauna Life makes no other representation or warranty, express or implied, either in fact or operation of law, statute, or otherwise, and Sauna Life specifically disclaims any and all implied or statutory warranties, including warranties or merchantability and of fitness for a particular purpose. Sauna Life shall not be liable for loss of use of the Sauna Life sauna or other incidental or consequential costs, expenses, or damage, which may include but are not limited to, the removal of or reinstallation of a wall, deck or other fixture, water leakage, costs of shipping or packaging, applicable taxes, or the payment of any costs or expenses of disassembly, removal, or reinstallation of the product or any part. Your rights may vary from state to state. Under no circumstances shall Sauna Life or its representatives be held liable for injury to any person or damage to any property, however arising, even if caused by the Sauna Life Sauna or its representatives’ negligence. No distributor, salesperson, dealer, retailer, or other representative of Sauna Life has the authority to alter or change these warranties either orally or in writing.

      Shipping & Returns

      Cancellations & Refunds: Sauna Heater Supply prides itself on having one of the best return policies in the industry. Cancel any time before your order has shipped, completely free of charge (exceptions apply, including custom made orders).

      Call 916-333-0240 or email sales@saunaheatersupply.com

      Frequently Asked Questions

      When will I know my order has shipped?

      As soon as you place your order, you will receive an order confirmation e-mail. This means that we have received your order in our system and pre-authorized your credit card for the purchase. As soon as we receive your order, we automatically reach out to our suppliers to confirm that it is in stock and available for immediate shipment. If your item is on backorder or unavailable, we will void the pre-authorization and reach out to you via e-mail. If your item(s) are available for immediate shipment (within 5 business days), we will process the charges and submit the order for shipment. If, for some reason, there is a delay in stock, we will contact you before accepting payment.

      When will my order ship?

      If your order is in stock and we process the charges to your credit card, it will ship within 2-5 business days from the date of your order. We will send you tracking information within 24 hours of your order leaving the warehouse to the e-mail address you provided when checking out. If you do not receive tracking information from us within six business days of your order, feel free to follow up with us at sales@saunaheatersupply.com.

      No Shipping outside the lower 48 in USA.

      If you have questions regarding anything below, please send an email to sales@saunaheatersupply.com or call us at 916-333-0240

      Cancellations & Refunds: At Sauna Heater Supply, we pride ourselves on having the best return policies in the industry. Cancel your order any time before it ships completely free of charge (exceptions apply such as custom orders, see below).

      If you have questions, please send an email to sales@saunaheatersupply.com or call us at 916-333-0240

      Cancellations (Before Order Ships)

      If you need to cancel an order, please contact us as soon as possible so we can refund you in full before your order leaves the warehouse. Reach agents during business hours at 916-333-0240, the chat in the bottom right, or email sales@saunaheatersupply.com any time.

      Cancellations of Custom Orders

      Custom or made to order products cannot be canceled or refunded as these products are put into production specifically for your order.

      These units, are custom made to your specification or created once you order. Once you place your order they start building your unit. Your warranty will guarantee you a fully functional and operational product. If it is not clear whether your order is custom or made to order, please message or call us.

      All sales are final for Custom made and Made-to-order products.

      Refunds and Returns

      If you need to exchange your product, you may do so. You, as the customer, are responsible for any shipping costs throughout any returns and exchange processes.

      Not all orders are available for return once they have shipped. We order our products directly from the manufacturer. Therefore, if the manufacturer will not permit us to return a product, we cannot offer you a return. This often varies on a case-by-case basis; please reach out to us if you would like specific information on your brand and/or product.

      Due to drastically increasing LTL/freight shipping costs, any outright returns will incur 25% cancellation fee + return shipping costs. If you are replacing the product with something else, we may be able to help you cover some of the costs depending on the product.

      Shipping Times

      We promise to do our best to get your order to you as soon as possible. We provide estimated shipping times on the product pages based upon what our suppliers and freight companies tell us, and those estimated shipping times may change or vary without notice (Due to supply chain issues, the steel mills behind on making metal, the manufacturers delayed because of the mills, the overwhelmingly demand on shipping, factory/warehouse and dock workers and so on).

      Order delays have proven to be unavoidable and outside of Sauna Heater Supply's control. While this might be frustrating, we ask you to please be patient and understanding with us in these tough times. We thank you for your business and appreciate your patience.

       

      Warranty

      Warranties vary depending upon the manufacturer - see individual product pages for details. Warranty damages occur over time and from use. If an item was damaged upon arrival, and not reported within 30 days, that is not a warranty claim.

      Contact sales@saunaheatersupply.com for any questions.

      BY USING THE SITE, YOU AGREE TO THESE TERMS OF USE; IF YOU DO NOT AGREE, DO NOT USE THE SITE.

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      Ready for Your Hot Tub Party

      Ready for Your Hot Tub Party

      The SaunaLife SOAK-Series Model S4B is designed with convenience in mind, arriving completely assembled and ready for quick setup. This wood-burning hot tub is spacious, comfortably fitting up to six people, making it ideal for gatherings or relaxation with loved ones. The ergonomic fiberglass tub ensures a comfortable seating experience for everyone, while the exterior is made from thermally enhanced spruce for added durability and resistance to weather.

      The interior surface of the tub is easy to maintain, requiring minimal effort to keep it clean after each use. Its design is built to enhance your outdoor experience, ensuring that you and your guests can fully enjoy the hot tub without worrying about upkeep. Whether hosting a hot tub party or enjoying a quiet soak, the Model S4B provides a luxurious and practical solution for all your outdoor relaxation needs.

      Explore SaunaLife
      Engineered for Efficiency and Performance

      Engineered for Efficiency and Performance

      Crafted in Northern Europe, the Model S4B is engineered for superior efficiency and performance. This wood-burning hot tub heats water three times faster than traditional models, thanks to its innovative design. No electrical connection is required, and the advanced stove system maximizes heat transfer while minimizing wood consumption by up to 50% compared to other hot tubs.

      The self-cleaning corrugated stove with a secondary chamber optimizes the heat transfer from smoke, ensuring the water heats quickly and evenly. Additionally, the space between the fiberglass lining and the wooden exterior is heated to accelerate the warming process, contributing to the tub's rapid performance. This unique combination of materials and engineering creates a hot tub that is as efficient as it is effective.

      Shop All Saunas
      Start Enjoying Sooner

      Start Enjoying Sooner

      The fast-heating capabilities of the Model S4B wood-burning hot tub allow you to start relaxing sooner. This incredibly efficient stove heats up to 304 gallons of water from 40°F (5°C) to 95°F (35°C) in just 1.5 to 2 hours, making it the fastest-heating wood-fired hot tub on the market. The design ensures that you can enjoy a soothing soak without the long wait that traditional wood-burning tubs often require.

      This speed is a game-changer for anyone who wants to quickly enjoy the benefits of a hot tub without extensive heating times. Whether you’re in a hurry or just want to relax after a long day, the Model S4B ensures that you can start your soak in record time. Its innovative heating system brings you the luxury of fast and efficient warmth for any occasion.

      Explore SaunaLife
      Speak With An Expert:

      Speak With An Expert:

      Call, chat, or email now!

      Get quick answers and personalized advice and discounts for your project.

      📞 916-333-0240

      sales@saunaheatersupply.com

      Speak With An Expert: 916-333-0240
      Need Help Sizing Your Heater?

      Need Help Sizing Your Heater?

      Not sure what size heater you need?

      Click here to accurately size your heater! Your sauna will thank you :)

      In between sizes? We recommend sizing up - we've never had a customer complain about a heater being too warm!

      Find My Sauna Heater Size
      Still Have Questions About SaunaLife?

      Still Have Questions About SaunaLife?

      Our sauna heater experts are here to help.

      If you have any questions about SaunaLife, call us, or speak to us with the chat found from the bottom right corner.

      We are here to help!

      📞 916-333-0240

      sales@saunaheatersupply.com

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      Customer Reviews

      Overall rating: 4.6 / 5 from 18125 reviews.

      Customer photo review of HUUM HIVE Wood 13

      Great sauna when modified! Unfortunately, we had 2 birds fly in & get stuck in the stove because of the opening of the chimney, so we added chicken wire to the top to prevent that from happening again. We messaged the company about it too so hopefully they resolve this issue.

      HUUM HIVE Wood 13

      Customer photo review of Huum DROP Series Electric Sauna Heater - 9kW

      The HUUM Drop is a game-changer! Sleek design, powerful performance. It's transformed my sauna experience. Highly recommend for any sauna enthusiast.

      Huum DROP Series Electric Sauna Heater - 9kW

      Customer photo review of Huum HIVE Series Electric Sauna Heater - 12kW

      The Hive 12kw is a powerhouse! It took a bit to figure out the optimal settings, but now it's perfect. Sauna Heater Supply's customer service was top-notch when I had questions.

      Huum HIVE Series Electric Sauna Heater - 12kW

      Customer photo review of Huum STEEL Series Electric Sauna Heater - 6kW

      This 6kw Steel series heater is perfect for my home sauna. It looks amazing and performs even better. Sauna Heater Supply made the whole process so easy!

      Huum STEEL Series Electric Sauna Heater - 6kW

      Customer photo review of HUUM HIVE Wood Series 17kW Sauna Heater Package

      The Hive wood heater adds such a cozy atmosphere to my sauna. Love the traditional feel. Took some time to get used to, but now I wouldn't have it any other way.

      HUUM HIVE Wood Series 17kW Sauna Heater Package

      Customer photo review of Huum DROP Series Electric Sauna Heater - 4.5kW

      Compact powerhouse! Perfect for my small sauna. Easy install, heats quickly. Loving the Scandinavian design. Thx Sauna Heater Supply for the recomendation!

      Huum DROP Series Electric Sauna Heater - 4.5kW

      Very happy customer here. The stone capacity is generous so the heat stays even after adding water. The design looks modern and it has become the centerpiece of our sauna. Customer service answered all my questions before I ordered. Worth every dollar.

      Saunum AIR L 10 WiFi Sauna Heater Package

      Exactly what I was looking for. Build quality feels solid, thick steel and clean welds everywhere. The heat feels soft and even, no hot spots near the benches. We use it four or five times a week and it has been completely reliable. Thank you for a great product!

      HUUM DROP Electric Heater Package w/ Black UKU Wifi Controller and Stones

      Great heater and worth every penny. The heat feels soft and even, no hot spots near the benches. Our sauna gets to 175F in about 35 minutes, faster than our old heater. Customer service answered all my questions before I ordered. Would buy again without thinking twice.

      HUUM STEEL 6.0STU Pkg

      Great heater and worth every penny. Power use is reasonable, our electric bill barely noticed it. Compared to our last heater, the room heats more evenly top to bottom. It arrived two days earlier than the estimate. Would buy again without thinking twice.

      HUUM CLIFF 11STU Pkg

      Great sauna and worth every penny. Build quality is excellent, tight joints and smooth finished wood. My muscle soreness after workouts has improved a lot since we started using it. Ordering was easy and the tracking updates were accurate. Worth every dollar.

      Finnmark FD-4 Trinity Infra-Steam Sauna

      Top quality from start to finish. HUUM quality is obvious, thick plates and tight seams. The 17kW stove is sized perfectly for our cabin sauna. Ash removal is easy thanks to the well designed ash pan. It arrived two days earlier than the estimate. Ten out of ten.

      HUUM HIVE Wood LS 17ST Pkg

      Really good, just short of perfect. Saunum clearly put thought into the details, everything lines up well. The first run gave off a burning smell, which went away after the second session. We use it four or five times a week and it has been completely reliable. Overall a good buy.

      Saunum Air L 13 Sauna Heater Package

      Could not be happier with this purchase. Steam is fantastic, water on the stones gives long, gentle waves of loyly. Temperature stays within a couple of degrees once it reaches the set point. Support was friendly and knowledgeable when I called. You will not be disappointed.

      HUUM CLIFF 9

      Very happy customer here. Exactly as described on the product page. The thermo aspen frame and handle look beautiful. The hinges are sturdy and the door closes smoothly. Shipping was quick and everything arrived well packed. Thank you for a great product!

      ProSaunas Clear Glass Sauna Door 24x73 Thermo-Aspen

      So glad we finally ordered this. It lights easily and gets the sauna to 180F in under an hour. Heavy, solid steel construction that feels like it will last decades. The team followed up after delivery to make sure everything was fine. No regrets at all.

      HUUM HIVE Heat LS 12ST Pkg

      Would give 4.5 stars if I could. Temperature stays within a couple of degrees once it reaches the set point. The first run gave off a burning smell, which went away after the second session. We use it after long days at work and it is the best part of the evening. Good value overall.

      HUUM HIVE Mini 11

      Could not be happier with this purchase. It burns wood efficiently, we use far fewer logs than with our old stove. Works perfectly off-grid at our lake cabin, no electricity needed. The stones hold heat for a long time, great steam even as the fire dies down. Would buy again without thinking twice.

      HUUM HIVE Wood 13

      SaunaGear really knows what they are doing. SaunaGear makes great sauna products and this is no exception. Exactly as described on the product page. It keeps our electrical connections dry and protected outdoors. Plenty of room inside for the contactor and wiring. No regrets at all.

      SaunaLife Waterproof Sauna Equipment Electrical Enclosure XL

      Very happy customer here. Nippa quality is obvious, thick plates and tight seams. Heavy, solid steel construction that feels like it will last decades. Ordering was easy and the tracking updates were accurate. Customer service answered all my questions before I ordered. Thank you for a great product!

      NIPPA WB-T Sauna Tent Stove

      I did a lot of research before buying and I am glad I chose this one. Smooth on all four sides and ready to use without sanding. Stable in the heat, no warping after months of use. The team followed up after delivery to make sure everything was fine. Would buy again without thinking twice.

      PROSAUNAS CEDAR 2X4 STK S4SEE

      We have had this for a few months now and it is fantastic. Temperature readings match my separate thermometer. It looks sleek on the wall and matches our sauna interior. Packaging was solid and nothing was damaged. Customer service answered all my questions before I ordered. Thank you for a great product!

      Harvia Xenio CX45-U1-U3-XW

      Frustrating experience so far. It did not fit our heater model despite the listing. It took longer to arrive than I expected for a small part. The box arrived damaged and I had to wait for a replacement. The wrong part was shipped the first time. Cannot recommend at this point.

      HUUM SP0008

      Really impressed with this main module. HUUM makes great sauna products and this is no exception. It has held up well to the heat and humidity. Packaging was solid and nothing was damaged. Ordering was easy and the tracking updates were accurate. You will not be disappointed.

      HUUM UKU-LOCAL-MODULE

      Narvi really knows what they are doing. Works perfectly with our home sauna setup. The black finish matches our stove perfectly. Customer service answered all my questions before I ordered. Support was friendly and knowledgeable when I called. Would buy again without thinking twice.

      Narvi Flue Extension Flue Extension, Black

      Really good, just short of perfect. Good quality components and no flicker at all. The transformer must be mounted outside the sauna, so plan for that. Shipping was quick and everything arrived well packed. Ordering was easy and the tracking updates were accurate. Still recommend it.

      ProSaunas Universal Sauna Light Kit with 16-Ft Flexible LED Strip

      Not what I hoped for. It cracked after a few uses in the heat. The box arrived damaged and I had to wait for a replacement. The effect fades quicker than I hoped. Delivery was delayed by almost two weeks and updates were slow. Cannot recommend at this point.

      Hukka SaunaSimo Sauna Fountain

      Happy with this fountain, with one small caveat. Works perfectly with our home sauna setup. Smaller than it looked in the photos. Customer service answered all my questions before I ordered. Shipping was quick and everything arrived well packed. Good value overall.

      Hukka Solina Sauna Fountain

      Could not be happier with this purchase. Hands free steam is a luxury we did not know we needed. It has held up well to the heat and humidity. Support was friendly and knowledgeable when I called. It arrived two days earlier than the estimate. Ten out of ten.

      Hukka Solina Sauna Fountain

      Dundalk LeisureCraft really knows what they are doing. Nice finishing details, you can tell it is a quality brand. Great value for the price. Packaging was solid and nothing was damaged. Rated for sauna heat and it has held up perfectly. Thank you for a great product!

      Dundalk LeisureCraft Electric Sauna Light

      Five stars, no hesitation. The quality is excellent and it looks exactly like the pictures. Nice finishing details, you can tell it is a quality brand. Packaging was solid and nothing was damaged. Ordering was easy and the tracking updates were accurate. Already recommended it to friends.

      Hukka Jolle Sauna Elf Friend with Stacked Cone Hat

      Frustrating experience so far. Support took several days to reply to my emails. The wrong part was shipped the first time. It did not fit our heater model despite the listing. The fit was slightly off and I had to adjust it. Hoping support sorts it out.

      HUUM Glass HH

      My second HUUM purchase and just as good as the first. The instructions were clear and all the hardware was included. Solid build quality, it feels as good as the original. Shipping was quick and everything arrived well packed. You will not be disappointed.

      HUUM Glass HH

      Really impressed with this heater. Our sauna gets to 175F in about 35 minutes, faster than our old heater. It is completely silent while running, just the hiss of water on the stones. Customer service answered all my questions before I ordered. Thank you for a great product!

      Harvia KIP30W

      Could not be happier with this purchase. We use it four or five times a week and it has been completely reliable. Compared to our last heater, the room heats more evenly top to bottom. The 4.5kW output is perfect for our room and holds temperature steadily. Highly recommend.

      HUUM DROP 4.5STU Pkg

      Top quality from start to finish. The 4.5kW output is perfect for our room and holds temperature steadily. The design looks modern and it has become the centerpiece of our sauna. It replaced an old heater that was over 20 years old. Highly recommend.

      HUUM DROP 4.5STU Pkg

      Could not be happier with this purchase. Power use is reasonable, our electric bill barely noticed it. Our sauna gets to 175F in about 35 minutes, faster than our old heater. The team followed up after delivery to make sure everything was fine. Highly recommend.

      Huum DROP Series Electric Sauna Heater - 4.5kW/6kW/7.5kW/9kW