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Wood Fired Hot Tub – Heater Options

Wood Fired Hot Tub Beautiful Location

Wood Fired Hot Tub – Heater Options

Wood Fired Hot Tub – Heater Options, when choosing one of our wood-fired hot tub the options are endless such as the output from the wood-fired stove.

This post will take a look at the different types of heater available for our wood-fired hot tubs and explain their pros and cons, so you can make an informed decision, ensuring that you have made the right choice with a Ten spa wood-fired hot tubs.

Wood Fired Heater Options – What We Offer?

Often confused with the hot tub type, the wood-fired stove that heats your tub is a fully customisable feature.  Considering that you’ll use the stove every time you hop in the tub, this gives you the freedom to choose a heater that suits your budget, your lifestyle, and the overall look of your wood-fired hot tub.

Wood-fired stoves for hot tubs can be categorised into 2 types:

So what’s the difference?

External Heaters

As the name suggestions an external heater sits on the outside of the hot tub, The heater is connected to the bathing water via two hoses, one for inlet and one for outlet.

External heaters can be fitted to any type of wood-fired hot tub, and tend to be the easiest to light and maintain, due to their ease of access.

While this ease makes them a favoured option for many customers, it should be noted that more space is required to position the stove alongside the hot tub, and safety provisions should be made to ensure that users (especially young children) are protected from the hot surfaces.

These heaters also allow more room within the hot tub itself because due to being separated from the hot tub itself, meaning more people can fit into a tub of a given size.

External heaters are available for the Tarkine (EX) and The Daintree (EX) hot tubs.

Internal Heaters

Internal heaters are installed within the bathing area of a wood-fired hot tub,separated by an insulated wall.  Our internal boilers tend to be the most budget-friendly heater option.

By integrating the internal heater into the hot tub body, it requires a lot less space in your garden, which makes internal heaters a perfect choice for locations where access around the hot tub is at a premium.

As internal heaters sit within the bathing water, their operation is very simple and they are highly efficient, with all heat from the stove body being transferred to the water itself, making the heating time quicker.

Because an internal heater sits within the wood-fired hot tub itself, they reduce the capacity of the hot tub by 1 – 2 people – This is something which should be considered when making your decision to purchase your new tub.


All wood-fired stoves need a chimney to vent the smoke from the fire that is heating your tub.  The chimney is connected to the stove itself, and vents vertically. Chimneys are usually 2 meters in Hight but can be extended if needs be.

When choosing the a suitable heater for your wood-fired hot tub you should consider the chimney with a view to safety, as they will get hot when the stove has been in use.  It’s important to ensure that users are protected from burns arising from contact with the flue, Chimney guards are an optional accessory to greatly reduce the chance of injury from contact with the hot metal.

Heater Output:  Should You Upgrade?

This is where heater selection can become very daunting… But don’t worry, we’ll give a short explanation as to why this matters to you (or why it may not).

Different heaters have different out-puts, at Ten Spa we offer multiple External heaters such as:

Our external square heaters are available in two different power capacities: 22 kW, and 28 kW. The choice of stove power depends on the amount of water you plan to heat. We recommend choosing the capacity of the stove according to the water capacity of the outdoor hot tub: 22 kW to 1200l of water, 28 kW to 1500l.

The external heaters are available in two different power capacities: 24 kW and 30 kW  The choice of stove power depends on the amount of water you plan to heat. We recommend choosing the capacity of the stove according to the water capacity of the outdoor hot tub: 24 kW to 1200l of water, 30 kW to 1500l . If you are planning to heat the hot tub during the winter season, we advise you to choose a more powerful stove.

An external 25kw pellet stove is a stove that burns compressed wood or biomass pellets to create a source of heat. By steadily feeding fuel from a storage container (hopper) into a burn chamber area, it produces a constant flame that doesn’t require any physical adjustments, this means that the water faster become warmer. it takes roughly about 30 minutes to heat.

The external round wood-burning stove with its big fuel chamber capacity, means you can put bigger and longer firewood in, thus ensuring a longer heating period.

Ten Spa currently offer 2 Internal heaters such as:

The internal immersion heater is designed for faster water heating because it is immersed inside the hot tub. it is designed to heat the water directly, without wasting heat on the environment, making it more efficient.

The internal immersion heater is designed for faster water heating because it is immersed inside the hot tub

What To Consider When Choosing Your Hot Tub Heater

Now you know the difference between the heater types available for Ten Spa wood-fired hot tub, which is the best for your tub?

These factors will determine the best choice for you.

Location & Accessibility

You’ve no doubt already got your eye on a spot to sit your new wood-fired hot tub, and its surroundings will play a part in choosing the best type of stove.

  • If your wood-fired tub is going to sit into an alcove, recess or corner, access in and out of the tub is going to be restricted to one or two sides of the tub.  With space around the tub at a premium, an external heater would take up valuable room and the reduced clearance would increase the chance of injury from contact with the stove.  In this case, an internal heater would be the more sensible option.
  • If your tub is going to sit in an open area, with free access around it an external heater is often favoured, to free up space within the hot tub itself and make cleaning and lighting easier.
  • In a rural garden, a wood-fired tub often sits into its surroundings seamlessly. Choosing an internal heater means that the exterior timber facade of the hot tub is unfettered giving a natural appearance and allowing the tub to blend into the landscape.
  • Where a wood-fired hot tub is installed for use by paying guests, such as a holiday let or glamping site, an internal heater is usually preferred.  Their inset fitting makes the chance of contact injuries very low, and their eye-catching nature and ease of use makes them a delight for guests.

Stove Access

Often overlooked by customers already immersed in the magical idea of owning and relaxing in their new wood-fired hot tub, access to the stove is required every time you use your tub, and for periodic cleaning of the ash pan.

While internal heaters have many benefits, they tend to be slightly more awkward to clean as everything has to be done low down.

In comparison, external heaters can be positioned freely away from the tub to ensure clear access all around for inspection, and keep the fire door easily accessible for both loading and lighting the fire as well as cleaning the ash when required.

In gardens where space is freely available and for customers who want to remove as many obstacles as possible between making the decision to enjoy and actually hopping in, external heaters are a firm favourite.

At Ten Spa we offer an addition extra of a fully mounted door with a glass panel, the sight of the roaring flame through the glass adds depth to the hot tub experience.


Ultimately, the heater choice very often comes down to personal preference and the budget you’re willing to spend on a wood-fired hot tub.

While considerations such as access and positioning are crucial in making sure your new wood-fired hot tub can be used safely and easily, the most important factor is choosing a heater that’s suitable for your garden and your budget.

With all things being equal, the heater is likely to be the last thing on your mind while you’re nestled back beneath the water enjoying the night sky and good company, but the wrong choice could cast a shadow over an experience that should be nothing less than delightful .

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