Overview

The SaunaLife Model S6B is a 436 gallon wood-fired soaking tub for outdoor use, seating up to 7 adults, with an integrated 304 stainless steel wood stove and no electrical connection of any kind. A wood-burning hot tub heats its water by burning firewood in a submerged or side-mounted stove instead of drawing power from a pump and heater element. You fill the S6B from a garden hose, light the stove, and soak. Water climbs from 40°F to about 95°F in 1.5 to 2 hours and tops out at 106°F. It arrives fully assembled on a pallet, so setup is placement, chimney fitting, and first fill.

Key Features

• Model S6B at a glance

• No jets, no pump, no filtration, no control panel

• Who is the Model S6B for?

• What does it need to sit on?

• Base must carry over 4,187 lbs filled. Level concrete, compacted gravel, or an engineer-rated deck.

• Chimney height is 106.3 inches. Confirm clearance from roof lines, trees, and fences.

• Some municipalities restrict outdoor wood burning. Check local rules before purchase.

• Firewood is not included. Maximum log length is 16 inches.

Product Benefits

This is a backyard soaking tub, not a spa. It suits households that want real hot tub capacity without an electrician, a permit for a dedicated circuit, or a monthly power bill. Cabin owners, lake properties, and off-grid builds are the core buyers, along with athletes who run heat and cold in the same session and want the heat side to work in a power outage. Groups of 4 to 7 get the most out of it. Most owners soak 20 to 30 minutes at a time, after training, after work, or through winter when a heated outdoor soak is the reason to go outside.

Do not buy the S6B if you want hydrotherapy jets, a thermostat you set and forget, or a tub ready in ten minutes. Those buyers should choose a plug-in electric spa. The S6B trades jets and instant temperature control for zero wiring and near-zero running cost. It is the wooden hot tub to pick when the property cannot support a spa's electrical load.

Placement decides whether this install goes well. Empty weight is 551 lbs. Filled with water and bathers it exceeds 4,187 lbs. That load needs a level, load-bearing base: a concrete pad, compacted gravel with pavers, or a deck a contractor has rated for the weight. The chimney stands 106.3 inches, so it needs clearance from eaves, fences, and overhanging branches. Firewood must be split to 16 inches or shorter.

Specifications

Ideal For

Off-grid and rural owners: no circuit, no electrician, works in an outage

Cabins and lake properties: seasonal use, drain and walk away

Entertainers: 6 or 7 seats instead of 4

Athletes: heat side of a contrast protocol with a cold plunge

Cold-climate households: wood heat is unaffected by air temperature

Not ideal for

Buyers who want hydrotherapy jets or a massage seat

Anyone who wants to set a temperature and walk away

Daily 6 a.m. users who cannot budget 1.5 to 2 hours of heat-up

Balconies, roof decks, or any surface not rated for the filled weight

Areas with burn bans or strict smoke ordinances

Wood-burning hot tub or electric spa: which should you buy?

Decision factor

Model S6B wood-fired

Typical electric spa

Install work

Place, fit chimney, fill

Dedicated circuit, electrician, often a permit

Running cost

Firewood only, no standing draw

Monthly electricity to hold temperature

Time to soak

1.5 to 2 hours from cold

Ready on demand

Jets and controls

None. Soaking only

Jets, lighting, digital panel

Water care

Treat and change. No filter circuit

Continuous filtration, cartridge changes

Power outage

Still works

Out of service

Moving it later

Drain and relocate, no rewiring

New circuit at the new location

How does the S6B stove work?

Corrugated firebox with a secondary chamber. Smoke passes through a second chamber and gives up its heat before it exits. SaunaLife rates the design at up to 50% less firewood than a standard wood-fired tub.

Faster climb than a conventional wood tub. SaunaLife rates the S6B at roughly one third the heat-up time of a traditional wood-fired hot tub.

Two-channel water flow. The stove draws cooler water in through a lower channel and pushes heated water out through an upper channel. Temperature evens out without stirring.

Heated air gap. Air between the fiberglass liner and the wood shell warms during the burn, which speeds the climb to soaking temperature.

Self-cleaning burn path. Ash and creosote buildup stay low, so upkeep is emptying the ash tray rather than scrubbing a flue.

304 stainless steel construction. Stove and polished chimney both handle constant wet-dry cycling outdoors.

Why GooFitness carries this

SaunaLife builds in Northern Europe, where wood-fired soaking is ordinary home practice rather than a novelty. The S6B is the largest tub in the Soak Series and the one we recommend when a customer wants capacity without a wiring project. We stock the sauna side of the range too, so a SaunaLife barrel sauna and tub pairing ships from one supplier on one order.

Recovery specialists on the contact us at support@goofitness.com, 9am to 6pm EST, Monday to Friday. Financing is available on high-ticket recovery equipment through Affirm and our equipment finance partners. Ask for a payment estimate before you order.

What do the specs actually mean?

Spec

What it means for you

436 gallon capacity

Water sits at chest height on most adults with 7 people in. Expect 2 to 3 hours to fill on a standard garden hose.

1.5 to 2 hour heat-up from 40°F

Light the stove when you get home, soak after dinner. Not a spontaneous tub.

106°F maximum temperature

Matches the upper limit of a conventional spa. You control it with how much wood you add.

No electrical connection

No electrician, no dedicated circuit, no monthly power draw. Works in an outage.

Black Thermo-Spruce shell, 1.65 in thick

Thermally modified wood handles rain, snow, and UV better than untreated softwood.

Contoured fiberglass liner

Shaped seating instead of a flat bench. Wipes clean, no interior wood to seal.

About 4,187 lbs filled

Concrete pad, compacted gravel, or a deck a contractor signs off on. Not a standard patio deck.

Steel-reinforced folding cover

Holds heat between soaks and folds in half, so one person can pull it off.

Integrated drain tap

Drain by gravity to a hose. No pump needed for a water change or winter shutdown.

Ships fully assembled

Position it, fit the chimney, fill it. No panel assembly or band tightening.

What ships with the Model S6B?

Fully assembled Model S6B tub with black Thermo-Spruce surround

Integrated 304 stainless steel wood-burning stove, dual heat compartments

Polished stainless steel chimney with protection, plus chimney cap

Matching Thermo-Spruce steps

Insulated steel-reinforced folding cover, dark grey marine-grade vinyl exterior

Drainage fitting with tap

Installation instructions

Also required, sold separately

Firewood, split to 16 inches or shorter

Level load-bearing base (concrete pad, gravel base, or rated deck)

Water treatment and test strips. The Spa Care Essentials 3-Month Maintenance Kit covers a first season.

How does the S6B compare to the other Soak Series tubs?

Model S6B

Model S4

Model S2B

Capacity

Up to 7 bathers

Up to 6 bathers

Up to 2 bathers

Water volume

436 gallons

Smaller volume, faster heat

Plunge volume

Heat source

Integrated wood stove

Integrated wood stove

No heater. Hot or cold fill

Shel

Shipping & Delivery

Delivery is curbside on a pallet. You arrange the final move into the yard.

Frequently Asked Questions

What's the difference between this and the natural-wood S6N? Function is identical — the S6B is the same 436-gallon, 7-person wood-fired tub with a black Thermo-Spruce shell instead of the natural finish that weathers to silver-grey.

How fast does it heat and how hot does it get? Water climbs from 40°F to about 95°F in 1.5 to 2 hours from the submerged or side-mounted wood stove, topping out at 106°F.

Will it work during a power outage? Yes — the S6B has no electrical connection of any kind, so the heat side keeps working even when the power is out.

How is it delivered and set up? It ships assembled on a pallet via curbside freight; setup is placement, chimney fitting, and the first fill.

How much clearance does the chimney need? The chimney stands 106.3 inches, so confirm clearance from eaves, fences, and overhanging branches before it's installed.

Questions? Contact us at support@goofitness.com or visit goofitness.com.