HUUM STEEL 6 STEEL Series 6kW Sauna Heater
The HUUM STEEL 6 is a 6kW floor-standing electric sauna heater for rooms from 212 to 353 cubic feet with an extraordinarily small footprint and the tightest safety clearances in the HUUM lineup. The STEEL's defining characteristic is its slim 12.6"W x 12.6"D stainless steel pillar profile - a square cross-section tower that stands 38.4" tall and requires just 2" (5 cm) of clearance from walls on all sides. HUUM describes the design intent precisely: the STEEL is a slim electric sauna heater with remarkably small safety distances, which makes it perfect for saunas with limited spaces. Despite its compact footprint, the STEEL 6 holds 330 lbs of rounded olivine sauna stones (10 boxes, 3-5 cm diameter, sold separately) through an intelligent internal structure. An internal air duct within the heater body circulates air through the stone mass to increase heating speed by up to 25%. The UKU Local or UKU Wi-Fi controller is required for operation and sold separately - no UKU Extension Box is needed for the 6kW model. Max temperature: 230°F (110°C). SGS certified. 5-year limited warranty (excluding elements). Designed and made in Estonia by HUUM.
2" safety distances - the slimmest installation footprint in the HUUM electric lineup
HUUM built the STEEL around a single clear design brief: minimize safety distances to make large stone-capacity electric heating possible in saunas where other heaters simply will not fit. At 2" (5 cm) from walls on all sides for the STEEL 6, the clearances are smaller than any other HUUM electric heater model. For a sauna room in the 212-353 cu ft range - often compact by design - the difference between 2" clearances and the 4-6" required by larger floor heaters can meaningfully change bench placement options and available floor space. With the optional HUUM Reflect S reflector panel accessory, the safety distances can be halved even further. The optional STEEL safety railing (light wood profiles, sold separately) adds a protective guard around the heater for sessions with children or when additional bather safety is preferred.
330 lbs of stones and an internal air duct for faster heat-up
The STEEL 6's 330-lb stone capacity (10 boxes, 3-5 cm rounded olivine stones) is disproportionately large for its footprint - this is by design. HUUM's own description of the engineering logic: because of its intelligent design, the STEEL has a much higher stone capacity than other heaters, providing more consistent, high heat, better steam capability, and an elevated bathing experience. The internal air duct system is the key structural feature that makes this possible: air is channelled through the stone mass in a controlled pattern that distributes heat through the full stone column efficiently and increases heating speed by up to 25% compared to a heater without an air duct. The 330-lb stone load then sustains that heat long into the session, producing consistent soft steam with each ladle of water. Stones are 3-5 cm rounded olivine - slightly smaller than the 5-10 cm stones used in the HIVE Electric series.
UKU controller required - Local or Wi-Fi, no Extension Box at 6kW
The STEEL 6 requires a HUUM UKU controller for all operation - the heater has no built-in controls. Both UKU Local (physical panel) and UKU Wi-Fi (smartphone app via HUUM mobile app) controllers are compatible with the 6kW STEEL. An important distinction for buyers: the UKU Extension Box is not required for the STEEL 6. It is only required for HUUM heaters over 9kW (specifically 10.5kW and above). The UKU Wi-Fi controller enables remote preheating from a smartphone and integrates with lights, ventilation, and steamer functions when connected. Safety features built into all UKU controllers include door sensor, overheating protection, and child safety lock. 240V/1PH, 30A circuit breaker, 10AWG wire required. A licensed electrician is required for all wiring and installation.
6kW floor-standing electric sauna heater for rooms from 212 to 353 cubic feet. STEEL Series - slim 12.6"W x 12.6"D stainless steel pillar design. Tightest safety clearances in the HUUM electric lineup: just 2" (5 cm) from walls on all sides. Internal air duct increases heating speed by up to 25%. 330 lbs stones required (10 boxes, 3-5 cm rounded olivine, sold separately). UKU Local or UKU Wi-Fi controller required - sold separately. No UKU Extension Box required for 6kW. Max temperature 230°F. 240V/1PH - 30A circuit breaker - 10AWG. Dimensions: 12.6"W x 12.6"D x 38.4"H. Optional: Reflect S reflector panel (can halve safety distances); STEEL safety railing; embedding flanges. Pallet delivery - scheduled freight required. SGS certified. 5-year limited warranty (excluding elements). Designed and made in Estonia by HUUM.
6 kW 212 to 353 cu ft STEEL Series - slim 12.6"W x 12.6"D pillar design 2" safety clearances from walls - tightest in HUUM lineup Internal air duct - heats up to 25% faster 330 lbs stones required (10 boxes, 3-5 cm rounded olivine) UKU Local or UKU Wi-Fi controller required - sold separately No UKU Extension Box required for 6kW Max temperature 230°F 240V/1PH - 30A - 10AWG 12.6"W x 12.6"D x 38.4"H Optional Reflect S - can halve safety distances Optional STEEL safety railing Pallet delivery required SGS certified 5-year limited warranty (excl. elements) Designed and made in Estonia by HUUM
Specifications
Performance
| Power output |
6 kW |
| Fuel type |
Electric (240V/1PH) |
| Room volume |
212 to 353 cu ft |
| Max temperature |
230°F (110°C) |
| Stone capacity |
330 lbs (10 boxes, 3-5 cm rounded olivine) - sold separately |
| Stone size |
3-5 cm rounded olivine (1-2 in) |
| Air duct benefit |
Increases heating speed by up to 25% |
Safety distances
| All sides (6kW model) |
2 in (5 cm) - tightest in HUUM electric lineup |
| With Reflect S reflector panel |
Distances can be halved further (optional accessory) |
| Vs larger STEEL models |
Larger STEEL models require 4 in (10 cm) |
Electrical
| Voltage / phase |
240VAC, 1-phase, 60Hz |
| Circuit breaker |
30A |
| Wire size |
10AWG |
| 208V note |
Output reduces by 25% at 208V |
| Certification |
SGS certified |
| UKU Extension Box |
Not required for 6kW (required for 10.5kW+ only) |
Controller (required - sold separately)
| Compatible controllers |
UKU Local | UKU Wi-Fi | UKU Glass | UKU Mirror | UKU Gold |
| UKU Local |
Physical panel - temperature, timer, door sensor, safety features |
| UKU Wi-Fi |
Physical panel + smartphone remote via HUUM mobile app |
| UKU safety features |
Door sensor, overheating protection, child safety lock |
| Integration |
Compatible with lights, ventilation, and steamer functions |
Physical dimensions
| Width |
12.6 in (320 mm) |
| Depth |
12.6 in (320 mm) |
| Height |
38.4 in (975 mm) |
| Profile |
Square cross-section slim pillar |
| Delivery |
Scheduled pallet freight - appointment required |
Construction
| Body material |
Stainless steel |
| Internal structure |
Air duct for 25% faster heat-up |
| Stone contact |
Stones loaded internally - air duct channels heat through stone mass |
| Installation |
Floor-mounted, vertical orientation |
| Use environment |
Interior sauna - wet area |
Certifications and warranty
| Certifications |
SGS certified |
| Origin |
Designed and made in Estonia by HUUM |
| Warranty |
5-year limited warranty (excluding elements) |
Optional accessories (sold separately)
| Reflector panel |
HUUM Reflect S - can halve required safety distances |
| Safety railing |
HUUM STEEL safety railing (light wood profiles) |
| Embedding flanges |
Available for bench integration |
| North American adapter |
N/A - electric, no flue required |
What's included
HUUM STEEL 6 6kW floor-standing electric sauna heater with internal air duct
Installation and operation manual
5-year limited warranty (excluding elements)
Required (not included): 330 lbs sauna stones (10 boxes, 3-5 cm rounded olivine - an additional box is recommended); HUUM UKU controller (Local or Wi-Fi). No UKU Extension Box is required for the 6kW model. Optional accessories (sold separately): HUUM Reflect S reflector panel; HUUM STEEL safety railing; embedding flanges. A licensed electrician is required for all wiring: 240V/1PH, 30A circuit breaker, 10AWG wire.
Why the HUUM STEEL 6 stands out
2" safety clearances - the slimmest electric installation available
HUUM describes the STEEL's defining advantage directly: remarkably small safety distances, perfect for saunas with limited spaces. At 2" (5 cm) from walls on all sides, the STEEL 6 can be positioned in sauna rooms where no other HUUM electric heater would fit without consuming valuable bench space through required clearances. For a compact home sauna in the 212-353 cu ft range where every inch of floor area impacts usable bench space, 2" clearances versus the 4-6" required by conventional floor heaters is a meaningful difference. With the optional Reflect S reflector panel, those distances can be reduced even further. No other HUUM electric floor heater achieves 2" clearances - this is unique to the smaller STEEL models.
330 lbs of stones in a 12.6" x 12.6" pillar
Three hundred and thirty pounds of sauna stones in a 12.6" square footprint is an exceptional stone-to-footprint ratio. HUUM attributes this directly to the STEEL's intelligent internal design: a much higher stone capacity than other heaters, providing more consistent, high heat, better steam capability, and an elevated bathing experience. The internal air duct channels air through the stone mass to distribute heat evenly through the full stone column and ensures the stones are charged thoroughly during heat-up. For a 6kW heater in a 212-353 cu ft room, 330 lbs of stones means the thermal mass available per unit of floor space is exceptional - soft, consistent steam and long-lasting heat from a heater that takes up less floor space than many conventional alternatives.
Internal air duct - 25% faster heat-up
The internal air duct built into the STEEL's structure channels air through the stone mass in a controlled pattern, distributing heat through the full stone column more efficiently than in heaters where air simply circulates around the stones naturally. The result is a heat-up speed up to 25% faster than heaters without an air duct. For a 6kW heater in a compact sauna room, faster heat-up means a shorter wait from switch-on to bathing temperature - a practical benefit in everyday home sauna use where the heater is switched on shortly before the session rather than hours in advance.
UKU controller - Local or Wi-Fi, no Extension Box for 6kW
The STEEL 6 works with any HUUM UKU controller: UKU Local (physical panel only), UKU Wi-Fi (physical panel plus HUUM mobile app for smartphone remote control), UKU Glass, UKU Mirror, or UKU Gold. All UKU controllers include door sensor, overheating protection, and child safety lock as standard safety features, and can be integrated with sauna lights, ventilation, and steamer functions when connected. An important specification note: the UKU Extension Box is not required for the 6kW STEEL. It is only required for HUUM heaters above 9kW. This simplifies the installation and reduces the total number of components required to operate the heater.
Optional Reflect S panel - halve the clearances further
The optional HUUM Reflect S reflector panel (sold separately) mounts on the heater and deflects radiant heat away from adjacent walls. HUUM states that the Reflect S panel makes it possible to achieve half the standard safety distances. For a sauna installation where even the 2" standard STEEL clearances are constrained by existing bench or wall configurations, the Reflect S provides a path to even tighter positioning. The optional STEEL safety railing (light wood profiles, sold separately) provides a decorative and safety-oriented wooden guard around the heater - adding a natural material contrast to the stainless steel pillar and protecting bathers from accidental contact with the heated stone surface.
STEEL Series - 6kW through 10.5kW floor models and 3.5kW wall model
The H1006012 is the 6kW entry point of the HUUM STEEL floor heater series. The STEEL Series also includes larger floor-standing models: STEEL 9 (9kW) and STEEL 10.5 (10.5kW) for larger room ranges. STEEL 9 and 10.5 models require 4" (10 cm) clearances from walls rather than the 2" clearances of the STEEL 6. The STEEL 10.5 also requires the UKU Extension Box. The STEEL Series also includes a wall-mounted STEEL 3.5 (3.5kW), which HUUM describes as an even slimmer model suitable for very small sauna rooms. All STEEL heaters share the same slim pillar aesthetic, internal air duct design, rounded olivine stone specification (3-5 cm), SGS certification, and 5-year limited warranty. Designed and made in Estonia by HUUM. We are an authorized HUUM dealer.
About HUUM
Designed in Estonia - SGS Certified - STEEL Series - 2" Safety Clearances
HUUM STEEL 6. 6kW. 212-353 cu ft. 2" clearances. 330 lbs of stones. 25% faster heat-up.
HUUM is an Estonian sauna heater company. The STEEL 6 is a 6kW slim stainless steel pillar heater for compact home saunas - 2" safety clearances from walls (tightest in the HUUM lineup), internal air duct for 25% faster heat-up, 330 lbs of stones in a 12.6" x 12.6" footprint, and UKU controller compatibility for physical or smartphone remote operation. UKU controller and 330 lbs stones (10 boxes, 3-5 cm) required and sold separately. No UKU Extension Box required. Pallet delivery. We are an authorized HUUM dealer.
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6kW electric - 212-353 cu ft - STEEL slim pillar design
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2" safety clearances from walls - tightest in HUUM electric lineup
- 330 lbs stones required (10 boxes, 3-5 cm rounded olivine)
- Internal air duct - 25% faster heat-up
- UKU controller required (no Extension Box) - 240V/1PH - 30A - 10AWG
STEEL 6 vs HIVE Electric vs HIVE 12 - HUUM electric heater comparison
HUUM STEEL 6 vs HIVE 12 Electric vs STEEL 10.5 - choosing the right HUUM electric heater
Three HUUM electric heaters serve different room sizes and installation priorities. HUUM STEEL 6 H1006012 (this listing): 6kW, 212-353 cu ft, slim 12.6"W x 12.6"D pillar, 330 lbs stones (10 boxes, 3-5 cm), 2" clearances from walls, no UKU Extension Box required, single 30A breaker. Right for compact home saunas where tight clearances, a slim footprint, and the 6kW output range are the specification. HUUM STEEL 10.5: 10.5kW, larger room range, 4" clearances (larger body), UKU Extension Box required. Right when more output is needed and slightly wider clearances are acceptable. HUUM HIVE 12 Electric H1003012: 12kW, 424-636 cu ft, open cylindrical beehive design, very large stone capacity, 240V/1PH with dual 30A breakers, UKU Extension Box required. Right for larger rooms where the HIVE's cylindrical stone-column design and higher output are the specification. The STEEL 6 is the right choice when 2" wall clearances, a slim 12.6" pillar profile, and 6kW output for a 212-353 cu ft room are the priorities.
Manuals and Documents
Warranty
5-year limited warranty (excluding elements)
The HUUM STEEL 6 carries HUUM's 5-year limited warranty from the date of purchase. The warranty covers defects in manufacturing and materials under normal use and maintenance conditions. Heating elements are excluded from the 5-year term and carry a separate warranty period per the warranty document. The warranty does not cover damage caused by improper installation, failure to follow the installation and operating guidelines, use of incorrect stone type or size (decorative stones must not be used as they can break under heat; use only rounded olivine 3-5 cm), operating without the required stone load, or damage from inadequate electrical installation. HUUM recommends using rounded olivine sauna stones to complement the heater's design and achieve milder steam. Proof of purchase from an authorized HUUM dealer is required for warranty claims. We are an authorized HUUM dealer.
