Which sauna heater should you choose? Electric, wood-fired and bio-combi explained

How does a sauna work?

Let’s start with the basics of how a sauna works. A sauna heater is placed in a small, untreated wooden room. The heater heats up and heats the stones inside it. A small amount of water is poured onto the stones, creating a pleasant warmth, a typical sauna experience. A wood-fired heater creates the ultimate sauna experience, but an electric heater offers other advantages.

When purchasing a sauna, make sure you buy the heater from the same brand as these heaters are designed for specific saunas.

Electric sauna heaters

Electric sauna heaters are the most popular choice for domestic and residential use. They offer speed, convenience and consistent performance, making them ideal if you’re looking for a low maintenance and modern sauna experience.

Check out the Harvia Trendy X Heater!

Benefits of electric heaters

• Fast heat up time: Most electric heaters bring the sauna to 70–90°C within 25-35 minutes, depending on the size and insulation. 

• Consistent and controllable: With built-in thermostats and timers, you can set and maintain the exact temperature you want. 

• Compact design: Wall-mounted or floor standing with a smaller footprint than wood-burning stoves.

• Clean a quiet operation: No smoke, no ashes and no need for ventilation flues. 

• Safe and compliant: Manufactured to strict European safety standards with automatic shut-off and overheat protection.

An electric heater is best if you’re a homeowner looking for a simple and reliable solution and are a regular user of your sauna so want quick startup times. This option may also be best in urban and suburban settings where wood smoke may be restricted.

Installation requirements

An electric heater must be installed by a qualified electrician in accordance with UK building regulations. Most units above 6kW require a 230V single-phase or 400V three-phase supply.

Wood-fired sauna heaters

A wood-fired sauna heater provides an authentic, traditional Finnish experience. Lighting the fire, tending to the flames and hearing the crackle of wood as your sauna heats up naturally enhances your sauna experience.

Check out the Harvia Pro 20 Wood Burner Sauna Heater!

Benefits of wood-fired heaters

• Authenticity: Deep, radiant heat and spa-like ambience. This option is perfect for off-grid retreats and countryside properties. 

• No electricity needed: Ideal for rural gardens, cabins or locations without power. 

• Powerful heating performance: Capable of heating larger spaces with excellent stone heat retention. 

• Natural aromatherapy: Pour water mixed with essential oils onto the stones for a richer experience.

This option is perfect if you’re a sauna enthusiast that values the ritual and tradition around sauna usage. It’s also a great option for off-grid gardens or remote properties where there is no power supply.

Installation requirements

A wood-fired sauna heater requires a chimney or flue pipe to be installed through the roof or side wall of your sauna for proper ventilation and safety. You will need a fireproof floor plate and wall protection panels around the stove area to protect your sauna.

Bio-combi sauna heater (steam and dry sauna)

The bio-combi sauna heater combines the benefits of a dry Finnish sauna and a steam sauna in one unit. These high-end electric heaters feature a built-in water reservoir, allowing you to adjust the humidity levels and even add herbs or essential oils.

• 2-in-1 functionality: Switch between a classic dry sauna or a milder, steam-rich sauna session. 

• Customisable atmosphere: Control temperature and humidity independently for a tailored sauna experience. 

• Perfect for mixed use: Offers gentle steam sessions for beginners and full heat for more experienced users.

Installation requirements

This option requires a 230V or 400V power connection and a reliable water source for steam generation. It must be professionally installed with proper safety measures and requires additional space due to the water tank or reservoir.

Quick sauna heater comparison

Wood-fired heater

• Heat up time: 40-60 minutes

• Requires electricity: No

• Installation complexity: Moderate (chimney and fireproofing)

• Control system: Manual

• Steam function: Manual (with water on stones)

• Aroma options: Yes (with oil on stones)

• Maintenance: Ash, soot, chimney cleaning

• Best for: Off-grid, traditional experience

Electric heater

• Heat up time: 25-35 minutes

• Requires electricity: Yes

• Installation complexity: Easy to moderate (qualified electrician)

• Control system: Internal or external digital

• Steam function: Yes (limited to water on stones)

• Aroma options: Yes (with caution)

• Maintenance: Minimal (dusting, safety checks)

• Best for: Ease of use, urban areas

Bio-combi heater

• Heat up time: 30-40 minutes

• Requires electricity: Yes

• Installation complexity: Moderate (electrical and water set-up)

• Control system: External digital and humidity control

• Steam function: Built-in steam generator

• Aroma options: Yes (designed for aromatherapy use)

• Maintenance: Regular water reservoir and filter checks

• Best for: Spa-style luxury, multiple user types

Need help choosing? Let Tuin assist you

At Tuin, we stock a wide range of compatible sauna heaters to suit all of our sauna kits.

Our team can:

• Recommend the right heater for your chosen sauna model

• Provide installation advice and electrical spec guidance 

• Help you choose the right brand

Explore our full range of sauna accessories here. Or please contact our customer service team for more advice and guidance.