The HUUM STEEL 6.0STU Package is a complete sauna heater package for rooms from 177 to 318 cubic feet, including the STEEL 6kW floor-standing heater, UKU sauna control (Local Black or WiFi - selected at checkout), and 330 lbs of rounded olivine diabase sauna stones. The STEEL is a slender floor-standing tower heater in brushed stainless steel - a different design concept from every other HUUM heater in the range. The DROP is wall-mounted with a water-droplet form. The HIVE and HIVE Mini are open beehive cages with massive stone capacity. The CLIFF has a natural stone exterior surface. The STEEL is a clean, rectangular stainless steel tower - a precisely engineered vertical column that combines a 330-lb stone capacity with exceptionally small safety clearances and an integrated internal air duct, making it the appropriate choice when floor-standing format, large stone mass, and tight wall clearances are all required simultaneously for the 177-318 cu ft room range.
The STEEL design - slender stainless tower, minimal clearances, 330 lbs of stone
The HUUM STEEL heater is engineered for sauna rooms with limited space where a floor-standing heater needs to fit close to walls without consuming the usable bench and floor area. The safety clearance from surrounding walls at the 6kW output level is just 2" (5 cm) - among the smallest of any floor-standing electric sauna heater. The slender rectangular tower profile fits naturally against sauna walls without projecting far into the room. Despite this compact, wall-friendly geometry, the STEEL 6 carries 330 lbs of rounded olivine diabase stones - nearly three times the DROP 6's 122-lb wall-mounted stone load - producing the large stone mass that delivers soft, sustained, long-lasting steam from a floor-standing heater on a standard 30A residential circuit. The clean brushed stainless steel exterior suits contemporary sauna interiors with dark wood, slate, or modern material palettes where the heater should read as a precise industrial element rather than an organic or stone-surfaced form.
STEEL vs CLIFF vs DROP - three HUUM approaches to the same room range
For rooms from 177 to 318 cubic feet, three HUUM heater types are available. The DROP 6kW is wall-mounted with 122 lbs of stones on a 30A / 10 AWG circuit - the compact, wall-mounted choice for rooms where floor space is limited and smaller stone mass is acceptable. The CLIFF 6kW is a slender floor-standing tower with a natural stone exterior and 165 lbs of stones on a 30A / 10 AWG circuit - the choice when natural stone aesthetics and minimal clearances are the priority. The STEEL 6kW is a slender floor-standing stainless tower with 330 lbs of stones on a 30A / 10 AWG circuit - the choice when maximum stone mass in a floor-standing format with minimal clearances is the priority, in a clean stainless steel form. All three run on the same 30A / 10 AWG circuit. The decision is mounting type, stone mass, and exterior aesthetic.
Integrated air duct - 25% faster heat-up, extended element life
The STEEL's integrated internal air duct directs airflow efficiently through the 330-lb stone mass during the warm-up cycle, reducing heat-up time by approximately 25% and extending the life of the heating elements by reducing thermal stress. For a 177-318 cu ft sauna room at 6kW, this means a shorter time from switch-on to bathing temperature. The 10 boxes of 2"-4" rounded olivine diabase stones included in this package are the correct type and specification for the STEEL 6. Like all HUUM floor-standing heaters, the STEEL can be partially embedded into a sauna bench using the optional embedding flange for custom installations, and can be fitted with an optional safety railing to prevent contact with the hot heater body.
Complete 6kW floor-standing sauna heater package for rooms from 177 to 318 cubic feet. Includes STEEL 6kW heater, UKU control (Local Black or WiFi - select at checkout), and 330 lbs of rounded olivine diabase stones (10 boxes). Slim stainless steel tower - 2" safety clearance from walls at 6kW. 330 lbs stone capacity - nearly 3x the DROP 6kW wall-mounted heater. Integrated internal air duct - 25% faster heat-up, extended element life. No UKU Extension Box required. Single 30A breaker, 10 AWG wire - same as DROP 6kW. 240V / 1-phase. Adjustable legs. Bench-embedding possible. Max 230°F. SGS Listed. 5-year warranty (elements excluded). Made in Estonia by HUUM.
Complete package - control + 330 lbs stones included 6 kW 177 to 318 cu ft Slim stainless steel tower - floor-standing 2" safety clearance from walls 330 lb stone capacity - 10 boxes included Nearly 3x the DROP 6 wall-mounted stone mass Integrated air duct - 25% faster heat-up No UKU Extension Box required UKU Local Black or UKU WiFi - select at checkout HUUM app - iOS and Android (WiFi variant) Single 30A breaker - 10 AWG - 240V 1-phase SGS Listed - made in Estonia 5-year warranty (elements excluded)
Specifications
Electrical
| Power output |
6 kW |
| Voltage |
240V / 1-phase / 60 Hz |
| Amperage draw |
25 A |
| Circuit breaker required |
Single 30A (standard 2-pole - no GFI/GFCI) |
| Wire gauge |
10 AWG |
| UKU Extension Box required |
No - not required for 6kW |
| Certification |
SGS Listed |
Room sizing and stones
| Room volume |
177 to 318 cu ft |
| Stone capacity |
330 lbs (150 kg) |
| Stones included |
Yes - 10 boxes rounded olivine diabase |
| Stone size |
2" to 4" (5-10 cm) rounded |
| Max temperature |
230°F (110°C) |
Physical and clearances
| Profile |
Slim rectangular stainless steel tower |
| Safety clearance from walls |
2" (5 cm) at 6kW |
| Mounting |
Floor-standing with adjustable legs |
| Bench-embedding |
Possible - embedding flange sold separately |
| Air duct |
Integrated internal - 25% faster heat-up |
| Construction |
Brushed stainless steel |
| Origin |
Made in Estonia by HUUM |
Control options - select at checkout
| UKU Local Black |
Wall-mounted digital control - on-site operation |
| UKU WiFi |
Adds HUUM app remote preheat and scheduling |
| App |
HUUM app - iOS and Android (WiFi variant) |
| UKU Extension Box |
Not required for 6kW |
STEEL vs DROP vs CLIFF at 6kW
| STEEL 6kW (this listing) |
Floor-standing | Stainless tower | 330 lbs | 2" clearance |
| DROP 6kW |
Wall-mounted | Water-droplet | 122 lbs |
| CLIFF 6kW |
Floor-standing | Natural stone surface | 165 lbs | 2" clearance |
| Room coverage |
All three: 177-318 cu ft |
| Electrical |
All three: single 30A / 10 AWG |
STEEL series
| STEEL Mini 3.5kW |
Wall-mounted | 106-212 cu ft | 30A / 10 AWG |
| STEEL 6kW (this listing) |
177-318 cu ft | 30A / 10 AWG | 330 lbs |
| STEEL 9kW |
318-530 cu ft | 50A / 8 AWG | 330 lbs |
| STEEL 10.5kW |
353-706 cu ft | 50A / 8 AWG | 330 lbs + ext box |
What's included
HUUM STEEL 6kW floor-standing sauna heater - brushed stainless steel tower
UKU sauna control (Local Black or WiFi - selected at checkout)
Rounded olivine diabase sauna stones - 10 boxes (330 lbs)
Adjustable legs
Installation and operation manual
Optional accessories (sold separately): HUUM STEEL safety railing (recommended), STEEL embedding flange (for bench mounting), reflector panels (reduce wall clearances further). A licensed electrician is required for all electrical connections.
Why the HUUM STEEL 6.0STU Package stands out
330 lbs of stone on a standard 30A circuit
The STEEL 6 carries 330 lbs of rounded olivine diabase stones - nearly three times the DROP 6's 122 lbs and twice the CLIFF 6's 165 lbs - on the same standard single 30A / 10 AWG circuit. For buyers in the 177-318 cu ft range who want the maximum stone mass available at this output level and circuit specification, the STEEL is the answer.
2" safety clearance - fits tight spaces
The STEEL 6 requires only 2" (5 cm) safety clearance from surrounding walls - the same as the CLIFF 6, and among the smallest of any floor-standing heater at this output. For sauna rooms where wall and bench positioning leaves minimal space for the heater, the STEEL can be placed where wider or more projecting floor-standing heaters cannot.
Slim stainless tower - precise industrial aesthetic
The STEEL's brushed stainless steel rectangular tower reads as a precision industrial object in the sauna room - clean, straight-lined, and modern. For sauna interiors with dark timber, slate, concrete, or contemporary black finishes where the heater should integrate as a precise utilitarian form rather than an organic or stone-surfaced element, the STEEL is the appropriate aesthetic choice in the HUUM floor-standing range.
Integrated air duct - 25% faster heat-up
The integrated internal air duct directs airflow efficiently through the 330-lb stone mass, reducing heat-up time by approximately 25% and extending element life. For a 177-318 cu ft room at 6kW, this means reaching bathing temperature sooner. The improved airflow also distributes heat more evenly through the full stone load for consistent steam when water is ladled.
Floor-standing with bench-embedding option
The STEEL stands on adjustable legs directly on the sauna floor without wall mounting. The optional embedding flange allows partial installation into the sauna bench for custom built-in looks. The STEEL Mini 3.5kW wall-mounted variant is available separately for rooms where floor space is the constraint rather than wall space.
UKU WiFi - remote preheat
Upgrading to UKU WiFi at checkout adds HUUM app control on iOS and Android - remote preheat from anywhere, session scheduling, and temperature monitoring. No UKU Extension Box is required for the 6kW STEEL. For sauna rooms in the 177-318 cu ft range that take 20-35 minutes to reach temperature, the WiFi option removes the need to plan the warm-up in advance.
About HUUM
Made in Estonia - SGS Listed
HUUM STEEL 6STU. 6kW. 177-318 cu ft. 330 lbs of stone. Slim stainless tower. 2" from the wall.
HUUM is an Estonian sauna heater company. The STEEL is HUUM's slender stainless steel tower heater - a floor-standing unit engineered for maximum stone mass in minimum footprint at minimal wall clearances. At 6kW covering rooms from 177 to 318 cubic feet, the STEEL 6STU Package delivers 330 lbs of rounded olivine diabase stones and 25% faster heat-up from an integrated air duct, on a standard single 30A / 10 AWG residential circuit. The brushed stainless steel exterior suits contemporary sauna interiors where a clean industrial tower aesthetic is preferred. The package includes the STEEL 6kW heater, the UKU control (Local Black or WiFi at checkout), and 10 boxes of the correct rounded olivine stones. We are an authorized HUUM dealer.
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Complete package - STEEL 6kW, UKU control, and 330 lbs rounded olivine stones
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6kW, 177-318 cu ft - single 30A / 10 AWG, 240V/1PH
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330 lb stone capacity - largest stone mass of any 6kW HUUM on a 30A circuit
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2" from walls - minimal clearances for tight sauna room layouts
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No UKU Extension Box required - 5-year warranty (elements excluded)
STEEL series - 6kW, 9kW, 10.5kW floor-standing
STEEL 6 vs STEEL 9 vs STEEL 10.5 - choosing the right STEEL output
All three floor-standing STEEL models share the same slim stainless tower profile, 330-lb stone capacity, integrated air duct, 2"-4" (5-10 cm) safety clearances (with 4" applying to larger models), and adjustable leg installation. STEEL 6kW: 177-318 cu ft, single 30A / 10 AWG, no extension box. STEEL 9kW: 318-530 cu ft, single 50A / 8 AWG, no extension box. STEEL 10.5kW: 353-706 cu ft, single 50A / 8 AWG, UKU Extension Box required. To select the correct output level, calculate the adjusted cubic footage of the sauna room - accounting for cold surfaces such as glass, tile, and masonry panels that increase the effective thermal load. STEEL also offers a wall-mounted Mini 3.5kW model for rooms from 106-212 cu ft. A licensed electrician is required for all installations. No GFI/GFCI breakers. The optional STEEL safety railing is recommended.
Manuals and Documents
Warranty
5-year limited warranty (elements excluded)
The HUUM STEEL 6.0STU Package is covered by HUUM's 5-year limited warranty from the date of purchase. The warranty covers defects in manufacturing and materials under normal use conditions. Heating elements are excluded from the 5-year coverage and carry their own separate warranty period. The warranty does not cover damage caused by improper installation, use of incorrect or non-approved stones, operating the heater without the required stone load, or failure to follow HUUM's installation and operating guidelines. A licensed electrician is required for all electrical connections. Do not connect to a GFI/GFCI breaker. Proof of purchase from an authorized HUUM dealer is required. We are an authorized HUUM dealer.
