Mondex sauna heaters are built to last. If you already own a Mondex sauna heater, you can find your product’s user and maintenance manuals here.
If you are planning a sauna renovation and wondering how a sauna heater should be installed, or what the installation of an electric or wood-burning sauna stove requires, you’re in the right place. This guide explains what you need to know before, during and after installation to ensure your new sauna operates safely and provides perfect steam for years to come.
Before installing your sauna heater
When renovating a sauna, choosing and installing the right heater are key steps. The size and power of the sauna heater should always match the sauna’s dimensions and structure, but correct installation is just as important for safety and comfort.
Before installation, store the heater in its original packaging in a dry and warm place. For Mondex electric sauna heaters, the package includes the heater itself and, depending on the model, a thermostat sensor, electronic control unit, and necessary cables. The packaging protects the heater from moisture and impact. Check all parts before starting and contact your retailer if anything appears missing or damaged.
Protect the sauna floor before beginning the installation to prevent scratches or damage. Once the sauna heater is in place, adjust the leveling feet to ensure it stands straight and stable. If the heater will be recessed into the benches, plan the installation ahead so the electrician can safely connect the cables and control unit.
Always maintain the model-specific safety distances between the heater and combustible materials. This ensures safe operation and prevents the sauna structure from overheating.
Basic principles of sauna heater installation
- Placement and base: The sauna heater must be installed firmly on a level, heat-resistant, non-combustible surface. Wood-burning stoves require a protective base plate.
- Safety distances: Always follow the model-specific minimum distances and ensure proper air circulation around the heater.
- Connection or flue installation: Electric sauna heaters must be connected to the electrical system by a licensed electrician. Wood-burning sauna stoves are connected to a chimney according to the manufacturer’s instructions.
- Stone placement: Use only stones designed for sauna heaters, such as split-face olivine diabase. Stack them so that air can circulate freely—outer stones more tightly, inner stones more loosely. Overpacking may restrict airflow and cause overheating in electric heaters or the firebox of wood-burning ones.
Electric sauna heater wiring must be done by a professional
In Finland, the installation of an electric sauna heater is a licensed task. Only a certified electrician (S2 authorization) is allowed to perform the wiring. A professional ensures all regulations are met and that the installation is completely safe.
Incorrect wiring can cause overheating, electrical faults, or even fire, which is why professional installation is essential. You can find more information about electrical installation requirements for saunas on the Finnish Safety and Chemicals Agency (Tukes) website.
During installation, the electrician ensures the correct safety distances. For example, Mondex electric sauna heaters typically require a side clearance of 100–120 mm and a clearance above the heater of 770–1070 mm, depending on the model. These distances ensure proper heat distribution and protect the sauna structure from excessive heat.
If your sauna heater has a separate control panel, plan its location before installation. It can be placed in a bathroom or dressing room, allowing easy temperature adjustment without entering the hot sauna. The control panel fits directly into a standard light switch box.
Installing a wood-burning sauna stove – safety first
The charm of a wood-burning sauna stove lies in its natural heat and the cozy atmosphere of real fire. However, its installation requires precision and care. The key factors are correct safety distances and a properly made flue connection.
Safety distances to combustible materials always follow the manufacturer’s instructions. Typically, the required space is about 1000 mm in front of the heater and 500 mm to the sides and back. For example, the Mondex Klapi model requires 500 mm in front and only 250 mm to the sides and back, while the Motti model requires 500 mm in front and 300 mm to the sides and back. If protective shields are installed, these distances can be reduced: single-layer protection cuts them by about half, and double-layer protection by up to 75%.
Typical clearance above the heater is 800–1200 mm, and for electric sauna heaters at least 250 mm to the floor, unless it is a floor-standing model. These clearances can also be reduced by 25–50% with approved heat shielding. When installed on a wooden floor, a non-combustible base is required, extending 400 mm in front of the heater and 100 mm to the sides.
Wood-burning sauna stoves are connected to the chimney either from the top or rear. In Mondex models, the flue diameter is 115 mm and the draft should be at least –12 Pa. The connection is sealed with heat-resistant mineral wool, and the chimney must be swept regularly according to regulations. Before the first indoor use, fire the sauna heater outdoors or in a well-ventilated space to burn off surface treatment residues. Once cooled, fill it with stones and it’s ready for use.
Proper ventilation makes for a better sauna experience
Ventilation has a significant impact on both heater performance and steam quality. In electric saunas, the air intake should be placed about half a meter above the sauna heater, and the exhaust vent as low as possible on the opposite wall. This ensures the heater receives enough oxygen and that the heat circulates evenly.
In saunas with a wood-burning stove, intake air should be directed close to the heater, and the exhaust vent should be positioned high and as far away from the heater as possible. This ensures clean combustion and keeps the sauna air fresh throughout your session.
First use and heating the sauna heater
Before the first heating, remove all protective films and make sure the sauna heater is correctly filled with stones. During the first heating, an electric heater may emit a slight odor and a wood-burning one may smoke a little – this is normal and disappears quickly.
Electric sauna heaters are not designed for continuous use. The best steam quality is achieved with moderate heating, typically 30–60 minutes depending on the sauna’s size. Make sure the control unit or timer automatically switches off the power after heating. Once the installation is done correctly and the sauna is properly ventilated, the heater is ready to provide soft, safe steam for years to come.
Safety tips for sauna use
A safe sauna is a relaxing sauna. Keep these simple but essential principles in mind:
- Never cover the sauna heater or use it for drying clothes
- Always supervise children and persons with limited mobility when bathing
- Do not use the sauna under the influence of alcohol
- Before heating, make sure there are no flammable materials near the heater
These small habits prevent the most common sauna safety problems and extend the life of your heater.
Discover Mondex sauna heaters
Once your sauna heater installation and wiring are safely completed, it’s time to enjoy the perfect steam.
All Mondex sauna heaters are made in Ylivieska, Finland, and proudly carry the Key Flag Symbol. The Mondex collection includes sauna heaters designed for Finnish homes combining quality, design, and durability. Whether you dream of a modern electric sauna heater for effortless use or a traditional wood-burning one with the authentic feel of fire, Mondex has the perfect model for your sauna.
Explore Mondex sauna heaters and find the one that stands the test of time – and brings you the best steam year after year.
Mondex – The soul of the Finnish sauna.