Harvia Electric Sauna Heater: Single-Phase vs. Three-Phase Power Supply

At Alphasauna, we receive many questions from customers about saunas while selling sauna rooms. One of the most frequently asked questions is: “How should I choose between single-phase and three-phase power for my Harvia electric sauna heater?”

The answer depends on the power supply voltage in your country. Harvia Electric Sauna Heaters must be matched with the correct voltage and power supply to ensure proper operation. Incorrect matching can not only render the heater unusable but may also lead to unnecessary losses.

Through this article, Alphasauna provides a professional Harvia Electric Sauna Heater Purchasing Guide, explaining how to match single-phase or three-phase electric sauna heaters based on different country specifications, along with important considerations for using sauna heaters.

What Is the Difference Between Single-Phase and Three-Phase Power Supply for a Harvia Electric Sauna Heater?

Single-phase and three-phase power supplies are two different types of AC power distribution. Simply put:

Single-phase power supply (220V/240V) is suitable for small home sauna rooms with heaters ranging from 3kW to 6kW.

Three-phase power supply (380V/480V) is more suitable for large sauna rooms, industrial settings, and high-power equipment (≥6kW).

Common Misconceptions:

1.Three-phase power consumes more electricity – In reality, power consumption is determined by the heater’s wattage, not the number of phases.

2.Three-phase power is more dangerous than single-phase power – The risk is related to voltage and current levels, not the number of phases.

How to Use Harvia Electric Sauna Heaters in Different Countries

Harvia is a well-known sauna heater brand from Finland. It primarily produces heaters that follow European standards (230V/400V, 50Hz) and North American standards (240V, 60Hz). Since voltage standards and power supply methods vary by country, the compatibility of Harvia electric sauna heaters should be determined based on local power requirements.

Below, Alphasauna has compiled key information to serve as a reference for selecting the right Harvia sauna heater for your location.

North America

In North America, most household power supply systems use a single-phase, three-wire configuration (220V-240V, 60Hz), consisting of two live wires (L1+L2) and one ground wire(PE). In contrast, commercial power supply systems use a three-phase, four-wire configuration (208V, 60Hz), consisting of three live wires (L1 + L2 + L3) and one ground wire（PE）.

The most commonly used Harvia electric sauna heater in North America is The Wall series (North American version). This series includes three power options: 4.5kW, 6kW, and 8kW. However, it is important to note that the SW45 model does not have ETL certification.

Therefore, 240V single-phase power is suitable for detached houses and home sauna rooms, while 208V three-phase power is ideal for commercial spaces and apartment buildings.

Below is the wiring diagram for the Harvia The Wall series (North American version) electric sauna heater.

Tips:

Why is the voltage called 110V?
The early North American power grid operated at 110V, but it was later upgraded to 120V. Despite this change, the term 110V is still widely used.

Is U.S. voltage simply 110V + 110V = 220V?
No, the two live wires have a 180° phase difference, which results in 240V, not a simple arithmetic sum.

Can I use a 50Hz electric sauna heater in North America?
Yes, but you would need a frequency converter, which can be costly.

Europe

The voltage system in Europe differs from that in North America. It primarily includes:

A single-phase, two-wire system (230V, 50Hz) consisting of one live wire (L) and one neutral wire (N) or a single-phase, three-wire system (L1 + N + PE).
A three-phase, four-wire system (400V, 50Hz) consisting of L1 + L2 + L3 + N or a five-wire system (L1 + L2 + L3 + N + PE).

The most popular model in Europe is the Harvia BC series electric sauna heater. This series is available with both internal and external control options:

Internal control: Allows users to adjust the timer and power settings inside the sauna room.

External control: Enables users to operate the sauna heater outside the sauna room via a controller (including a WiFi-enabled model).

While the BC series remains a best-seller, those with larger sauna rooms may opt for the Harvia Cilindro series, which significantly improves heating efficiency. However, this model requires approximately five boxes of sauna stones for optimal performance.

Choosing the Right Voltage
For home use (power ≤6kW), a 230V, 50Hz single-phase connection is sufficient.
For commercial use or large sauna rooms (power >6kW), a 400V, 50Hz three-phase connection is recommended.
Below is the wiring diagram for the Harvia BC series electric sauna heater

Professional Tips:

1. Not all European households have access to three-phase electricity. It is recommended to consult an electrician to determine whether an upgrade is necessary for high-power sauna heaters.

2. Unlike in North America, Europe does not use a split-phase system. The standard single-phase voltage is 230V, eliminating the need for split-phase adjustments to reach 240V.

Australia

Australia’s standard voltage system is the same as Europe’s:
230V, 50Hz single-phase, available in a two-wire system (1 live wire (L) + 1 neutral wire (N)) or a three-wire system (L1 + N + PE).400V, 50Hz three-phase, available in a five-wire system (L1 + L2 + L3 + N + E).

In Australia, the Harvia The Wall stainless steel series is a popular CE-certified model, available in black and silver shell options. For home or small sauna rooms (power ≤6kW), a 230V single-phase three-wire configuration is suitable. For commercial or large sauna rooms (power ≥6kW), a 400V three-phase five-wire system is recommended. Below is the wiring diagram for The Wall series electric sauna heaters.

Japan

Japan has the lowest standard voltage in the world. The typical household voltage is single-phase, three-wire 100V, consisting of two live wires (L1/L2) and one neutral wire (N). For commercial applications, the voltage is three-phase, three-wire 200V (L1/L2/L3). Additionally, Japan’s power frequency varies by region: Eastern Japan operates at 50Hz， Western Japan operates at 60Hz.

Due to this unique voltage system, Harvia has an exclusive distributor in Japan. While Harvia heaters may be more expensive there, they come with reliable after-sales support, ensuring quick solutions to any issues.

As an alternative, many people in Japan opt for Diooist electric sauna heaters, particularly the SAT series, which is a best-selling model. Like Harvia, it is available in internal control and external control versions.

If you need contact information for an official distributor, you can also reach out to Alphasauna suppliers. Below is the wiring diagram for the STA electric sauna heater.

South Korea

The standard voltage in South Korea is 220V, 60Hz single-phase, three-wire (L + N + PE), and 380V three-phase power, which can be either a four-wire system (L1 + L2 + L3 + N) or a five-wire system (L1 + L2 + L3 + N + PE).

When selecting a Harvia electric sauna heater, you can opt for the European version since its voltage is similar to South Korea’s. Most Harvia European version heaters support both 50Hz and 60Hz, but it is still essential to verify compatibility with your home power supply system before installation.

For homes and small saunas (220V, 60Hz single-phase), recommended models include:
Harvia The Wall, Vega, and Cilindro series with power options of 3kW, 4.5kW, and 6kW.

For commercial and large saunas (380V, 60Hz three-phase), recommended models include:
Harvia Club, Profi, and Virta series with power options of 8kW, 10.5kW, 15kW, and 20kW.

Even after selecting the right Harvia electric sauna heater, there are still many important usage details to keep in mind. Improper use can lead to damage to the sauna heater and reduce its lifespan.

Why Do Electric Sauna Heater Heating Elements Bend?

If your Harvia electric sauna heater experiences bent heating elements, there are two possible causes:

1.Natural Wear and Aging – Over time, prolonged use can cause the heating elements to degrade and bend.

2.Improper Sauna Stone Placement – Incorrectly placed sauna stones can obstruct heat distribution, leading to uneven heating and deformation of the elements during operation.

How to Properly Place Sauna Stones?

Proper sauna stone placement is essential—stones should not be randomly thrown in or stacked too tightly. Incorrect stacking can damage the heating elements and block air circulation, leading to overheating and a shorter lifespan for your electric sauna heater.

Correct Sauna Stone Placement:
Bottom Layer: Lay large stones flat at the bottom of the heater, maintaining 1–2 cm spacing in a structured arrangement.

Middle Layer: Place medium-sized stones in the middle, keeping 3–5 cm spacing to allow proper airflow. Avoid wedging stones tightly between the heating elements.

Top Layer: Position small stones on the top without applying direct pressure to the heating elements to prevent damage.

Following these guidelines ensures better heat distribution, improved air circulation, and an extended lifespan for your electric sauna heater.

Why Does My Electric Sauna Heater Work but Keep Making Crackling Noises?

If your electric sauna heater is functioning but produces a popcorn-like crackling noise, the issue is likely related to the sauna stones. These noises occur when the stones crack due to heat exposure.

Possible Causes:
1.Moisture or Impurities – Stones containing moisture or impurities may crack when exposed to high temperatures.

2.Incorrect Stone Type – Non-professional stones like granite or marble are prone to cracking and should not be used in sauna heaters.

Solution:
For optimal performance, use high-quality sauna stones such as volcanic rock, peridot, or gabbro, which can withstand extreme temperatures without cracking.

Why Choose to Buy Electric Sauna Heaters from AlphaSauna Supplier?

Alphasauna Supplier has a long-term partnership with Harvia and is a leading sauna product supplier in China, offering a wide range of high-quality sauna equipment along with excellent pre-sales and after-sales support.

Most importantly, Alphasauna is a one-stop supplier—eliminating the need to compare prices across multiple vendors. This ensures that you receive top-quality products at the most competitive prices with ease and convenience.