How Long Does It Take to Heat a Wood Fired Hot Tub (2–4 Hours Explained)

By Laura AndersenJanuary 08, 2026

Most wood fired hot tubs take between 1.5 and 4 hours to heat, depending on tub size, starting water temperature, outside conditions, and how the tub is built. Thanks to their insulated aluminium design and internal firebox, AlumiTubs consistently heat faster and retain heat longer than traditional wooden hot tubs.

How Long Does It Take to Heat an AlumiTub?

One of the most common questions we hear is: how long does it take to heat a wood fired hot tub?

With an AlumiTub, you can expect a typical heat time of 1.5–4 hours, depending on the size of the tub and your environment.

• AlumiTubs are available in three sizes, seating 2–10 people

• Ideal soaking temperature is 102–104°F

• Heat time is influenced by:

• Outdoor temperature

• Starting water temperature

• Firewood quality

• Insulation and setup

Once you reach your preferred soaking temperature, an AlumiTub will hold its heat indefinitely with as little as an armful of wood per day - something most traditional wooden tubs simply can’t match.

Why AlumiTubs Heat Faster Than Traditional Wooden Hot Tubs

Not all wood fired hot tubs are created equal. The AlumiTub was pioneered in 2001 specifically to outperform and outlast traditional wooden hot tubs with its marine grade aluminum construction, extra large and internally submerged firebox, 360 degrees of insulation, and stainless steel and cedar components that make its performance, function, ease and longevity unmatched.

The Problem With Unlined Wooden Hot Tubs

Traditional cedar tubs without a lining lose heat through the walls and base once the wood becomes saturated. Wet wood allows heat to pass through, meaning:

Longer heat times
More firewood required
Faster temperature loss between soaks

Why AlumiTubs Are More Efficient

AlumiTubs are designed from the ground up for wood fired hot tub efficiency:

Marine-grade aluminium lining that prevents heat loss
360 degrees of insulation around the tub, base, and on the water's surface which is then topped with an insulated lid
Internally submerged, extra large firebox for direct water heating, regular size logs that make for less smoke, less wood consumption, and less waste

Unlike external fireboxes, an internal firebox uses natural convection to heat the water directly. This design:

Reduces heat time
Uses less firewood
Produces minimal smoke when dry wood is used

The result is one of the fastest-heating wood fired hot tubs on the market, even in extreme winter conditions.

How to Heat Your Wood Fired Hot Tub (Step by Step)

If you’re new to wood fired hot tubs, here’s a simple process to follow:

Start with kindling

Place several pieces of kindling (1–4 inches in diameter) into the firebox.
Allow airflow

Rest the stove lid partially on the firebox to act as a damper.
Build the fire gradually

As the fire establishes, add larger logs as you would in a wood stove.
Monitor the thermometer

Once the water reaches 90°F, stop adding wood.
Let residual heat finish the job

The temperature will naturally rise to 102–104°F without overshooting.

Tips to Heat a Wood Fired Hot Tub Faster

If reducing heat time is important to you, these wood fired hot tub heating tips can make a significant difference—especially in cold climates.

1. Insulate the Base

Place rigid insulation beneath your tub. Many owners hide it with a stainless steel bottom band and report up to an hour faster heat time.

2. Insulate the Lid

Use the provided insulation under the lid while heating and between uses. Overnight heat loss can be limited to just a few degrees.

3. Insulate the Walls

Wrap your hot tub in insulation between the aluminium tub and cedar cladding to retain heat longer.

4. Use Only Dry Firewood

Dry, high-quality firewood burns hotter and cleaner. Wet wood causes smoke, poor combustion, and slower heating.

5. Stir the Water

Use a paddle or long piece of wood (about 4 ft) to circulate water from the bottom of the tub. This distributes heat evenly and speeds up the process.

Adding wood beyond 90 degrees farenheit can cause the water to overheat, requiring cooling with fresh water to bring it back down to hot tubbing temperature.

Using Dual Heating or Backup Heat Sources

If heating your wood fired hot tub fast is a top priority, AlumiTubs can be configured with a secondary heat source as part of the Hybrid system which includes the wood fired as well as a built-in electric heating and filtration system that can be managed virtually or on the tub itself for indefinite set-it and forget-it temperature management.

This option is ideal for:

• Airbnb hosts

• Residential installations

• Owners who want set-and-forget convenience

With dual heating, heat time can be reduced to just over an hour for standard-size tubs. It also allows you to maintain temperature while away skiing, fishing, or enjoying the day—without tending the fire.

Why Speed Isn’t Always the Goal

While it’s absolutely possible to heat a wood fired hot tub fast, speed isn’t the heart of the experience.

A wood fired hot tub invites a slower rhythm:

• Chopping wood

• Filling the tub

• Stoking the fire

• Letting anticipation build

It’s the difference between fast food and a home-cooked meal - or instant coffee versus a French press on a Sunday morning.

There’s a unique satisfaction in tending the fire, listening to it crackle, and easing into water you warmed yourself. The ritual is part of the reward.

A wood fired hot tub isn’t just about getting warm - it’s about slowing down, reconnecting, and enjoying the process as much as the soak.

Wood fired cedar hot tub with man standing inside it