• Space-saving, childproof and soothing
  • Also available as SANARIUM with SaunaPUR

Space-saving, childproof and soothing

With good heat, you can see the satisfied smile on the faces of all sauna-goers. Cleverly stowed under the seat, the Bonatherm under bench heating system ensures an even temperature distribution and pleasant climate. It is also childproof and allows for extra space within the sauna.


Under bench heating system

The BONATHERM heater is conveniently hidden under the sauna benches.

Pleasant climate

The KLAFS BONATHERM under bench heating system offers the perfect heat distribution.


With the BONATHERM under bench heating system, you eliminate the risk of burns from children's hands. Meanwhile it is still a fully-fledged sauna heater and creates the perfect sauna climate.

BONATHERM equipment

BONATHERM sauna heater

BONATHERM under bench heater

With its anthracite-colored outer casing, the heater is inconspicuously positioned in a space-saving way under the benches. The large-area air outlet results in an even heat distribution. A filling quantity of approx. 100 kg of original Finnish olivine stones in a large stone basket ensures long heat storage and intensive infusions.


The BONATHERM under bench heater is equipped with an integrated steam generator, as well as a steam outlet and removable aroma cup for scenting. The BONATHERM Aquapanel has a large level indicator for reading the water level. The filling can, specially developed for the SANARIUM®, allows easy filling of the steam generator and draining of the residual water.

BONATHERM infusion flap

The discreet infusion flap, which is embedded in the bench facing, harmoniously rounds off the BONATHERM concept and can be easily folded in and out with the help of a magnetic lock. This makes it easy to create steam.


  • BONATHERM sauna heating system for space-saving installation under the benches
  • VDE-tested
  • with large-area air outlet, air guide hood and additional air guide plate
  • Together with the KLAFS sauna control unit 21029, the SaunaPUR® function is possible, while together with the KLAFS sauna control unit 21033, the SANARIUM® function is possible.​​​​​

BONATHERM with 3.3 to 4.5 kW

  • Connected load 3.3 kW, 230 V for sauna volume 2.0 m³ to 4.5 m³
  • Connected load 4.5 kW, 230 V/400 V, for sauna volume 4.5 m³ to 7.0 m³
  • With stone filling of approximately 14 kg original Finnish olivine stones
  • 430 x 720 x 430 mm (H x W x D)
  • Wall mounting is possible without feet

BONATHERM with 6.0 to 9.0 kW

  • Connected load 6.0 kW, 230 V/400 V for sauna volume 7.0 m³ to 8.4 m³
  • Connected load 9.0 kW, 230 V/400 V, for sauna volume 8.5 m³ to 15.0 m³
  • Large stone basket for a filling quantity of approximately 100 kg original Finnish olivine stones for long heat storage and intensive infusions
  • 780 x 1,200x 570 mm (H x W x D)
  • Heater weight approximately 150 kg (including olivine sauna stones)

Find your nearest KLAFS partners

Select your country to find find your nearest KLAFS partners and contact them today.

BONATHERM under bench heater

The BONATHERM heater is conveniently hidden under the sauna benches, creating space for additional seating and ensures the heat is particularly balanced throughout the sauna for all the family to enjoy.  play to generate additional heat to your cabin environment. The discreet infusion flap embedded in the lounger cover rounds off the BONATHERM concept harmoniously and can be easily folded in and out with the help of a magnetic fastener. The infusion flap makes it child's play to generate an additional heat boost to your sauna. 

Take detailed advice from one of our expert consultants  about your spa planning. Not only when it comes to sauna technology, but also when it comes to bathing procedures and design, we will be happy to talk to you. 

KLAFS global
KLAFS products are only available from KLAFS. Contact your KLAFS partner now to find the right product for your needs and requirements.
Find KLAFS Partner
Contact KLAFS
Do you have any questions about the KLAFS company or our products? We will be happy to get back to you!
Contact KLAFS
Order Catalogue
Get inspiration around sauna, spa and wellness with our free catalogues.
Order catalogue