HUUM HIVE 18 HIVE Series 18.0kW Sauna Heater
The HUUM HIVE 15 is a 15kW floor-standing electric sauna heater for rooms from 530 to 813 cubic feet, with the distinctive open beehive cage form. This listing is the heater only. A UKU control unit, UKU Extension Box, and sauna stones are all required for operation and sold separately. The HIVE 15 is the top-output model in the HUUM HIVE floor-standing series - the highest output and largest room coverage of any full-size HIVE, for rooms from 530 to 813 cubic feet on a dual 50A / 8 AWG circuit configuration. The UKU Extension Box is required at 15kW and must be purchased alongside the control and stones when ordering this standalone heater. For a complete installation in a single purchase, see the HUUM HIVE 15STU Package at BathingBrands.
Top of the HIVE series - 15kW and 530-813 cu ft
The full-size HUUM HIVE series runs at two output levels: HIVE 12 (12kW, 424-636 cu ft, dual 30A / 10 AWG) and HIVE 15 (15kW, 530-813 cu ft, dual 50A / 8 AWG). The HIVE 15 is the higher output, for the larger room range - the top of the full-size HIVE family. For large dedicated sauna rooms from 530 to 813 cubic feet, commercial sauna installations, and high-capacity residential applications where the HIVE 12's 636 cu ft ceiling is insufficient, the HIVE 15 is the correct HIVE choice. Both models use the same 18.11" (460 mm) open beehive cage form and 528-lb stone capacity - the difference is output, room range, and electrical specification. The HIVE 15's dual 50A / 8 AWG circuit is heavier than the HIVE 12's dual 30A / 10 AWG: two 50A breaker slots and two 8 AWG wire runs are required.
Dual 50A / 8 AWG - the heaviest HIVE electrical configuration
The HIVE 15 requires two separate 50A / 8 AWG circuits - two 50A breaker slots in the electrical panel and two separate 8 AWG wire runs from the panel to the heater location. This is the heaviest electrical specification of any HUUM HIVE model: the HIVE 12 uses dual 30A / 10 AWG (lighter), and the HIVE Mini series uses single circuits at 30A, 50A, or 50A depending on model. Confirm the electrical panel has two available 50A slots before ordering. Two separate circuits means the wire run planning must account for both cables running to the heater location simultaneously. A licensed electrician is required for both circuit connections. Do not connect to GFI/GFCI breakers.
528 lbs of stones and three required components
As with the HIVE 12, the HIVE 15 requires three separate component purchases alongside the heater: a UKU control unit (Local Black or WiFi), a UKU Extension Box (required at 15kW), and 528 lbs of 2"-4" (5-10 cm) rounded olivine diabase stones. All three are sold separately at BathingBrands. The HIVE 15STU Package bundles all four components (heater, control, Extension Box, and stones) in a single purchase. When ordering the standalone heater, confirm all three required components are included in the order before checkout.
15kW floor-standing sauna heater for rooms from 530 to 813 cubic feet. Top of the HIVE series. Open 18.11" beehive cage form. 528 lbs stone capacity - 2"-4" rounded olivine. Dual 50A / 8 AWG circuits - two separate 50A breakers and 8 AWG wire runs required. UKU Extension Box required - not included in this listing. Required (all sold separately): UKU control (Local Black or WiFi); UKU Extension Box; 528 lbs stones. SGS Listed. 5-year warranty (elements excluded). Made in Estonia by HUUM. See HIVE 15STU Package for complete bundled purchase.
HUUM HIVE 15kW floor-standing sauna heater - 18.11" open beehive cage
Installation and operation manual
Top of the HIVE series - 530-813 cu ft
The HIVE 15 covers the largest room range of any full-size HIVE model - 530 to 813 cubic feet. For large dedicated sauna rooms, commercial sauna facilities, and high-capacity installations where the HIVE 12's 636 cu ft ceiling is insufficient, the HIVE 15 is the correct and only full-size HIVE choice. At 813 cu ft it covers some of the largest room volumes served by any residential-grade HUUM heater.
Same beehive cage as HIVE 12 - more output
The HIVE 15 uses the same 18.11" open beehive cage form as the HIVE 12 and the same 528-lb stone capacity. The visible difference in the sauna room between the two models is zero - the same stone column, the same cage diameter, the same visual presence. The difference is entirely in the output (15kW vs 12kW), the room range (530-813 vs 424-636 cu ft), and the heavier dual 50A / 8 AWG circuit.
528 lbs of stone at 15kW - peak HIVE performance
At 15kW driving 528 lbs of stone mass, the HIVE 15 produces the fastest heat-up of any full-size HIVE model in the large rooms it serves and the greatest capacity to sustain temperature through continuous back-to-back commercial sessions. For a 530-813 cu ft sauna room with multiple bathers in rotation, the 528-lb stone load at 15kW provides the thermal reserve and recovery time that smaller heaters and lighter stone loads cannot match.
Dual 50A / 8 AWG - heaviest HIVE circuit
Two separate 50A breakers and two 8 AWG wire runs are the heaviest electrical specification of any HUUM HIVE heater. Confirm the panel has two available 50A slots before ordering. The HIVE 12 uses dual 30A / 10 AWG - if a lighter dual-circuit configuration is acceptable for the room size, the HIVE 12 is the less demanding electrical option where the room falls within the 424-636 cu ft overlap.
Extension Box required - essential at 15kW
The UKU Extension Box is required for the HIVE 15 and is not included in this standalone listing. It is included in the HIVE 15STU Package. When ordering the standalone heater, add the Extension Box to the order with the UKU control and stones. Three separate item purchases are required: control, Extension Box, and stones. The HIVE 15STU Package bundles all four components in one purchase.
HIVE 15STU Package - the complete purchase path
The HIVE 15STU Package at BathingBrands bundles the HIVE 15 heater, UKU control (Local Black or WiFi at checkout), UKU Extension Box, and 528 lbs of stones in a single purchase. For most new HIVE 15 installations, the Package is the more convenient option. This standalone listing is for buyers replacing just the heater in an existing HIVE 15 installation or sourcing components individually for a staged purchase.
HIVE 15 vs HIVE 12 - top vs entry full-size HIVE
HIVE 15 (dual 50A) vs HIVE 12 (dual 30A) - when each is correct
Both full-size HIVE models share the same 18.11" beehive cage form and 528-lb stone capacity. HIVE 12: 12kW, 424-636 cu ft, dual 30A / 10 AWG. HIVE 15: 15kW, 530-813 cu ft, dual 50A / 8 AWG. For rooms from 424-530 cu ft, the HIVE 12 is correct - it covers the range on the lighter dual 30A circuit. For rooms from 531-813 cu ft, the HIVE 15 is the only full-size HIVE option. For rooms in the 530-636 cu ft overlap zone, the HIVE 12 is adequate for standard well-insulated rooms; the HIVE 15 provides more output headroom for cold surfaces or high-frequency commercial use. The HIVE 15's dual 50A / 8 AWG requirement is significantly heavier than the HIVE 12's dual 30A / 10 AWG - confirm panel capacity for both 50A slots before selecting the HIVE 15 in a borderline room. Both require the UKU Extension Box. A licensed electrician is required for both. Do not connect to GFI/GFCI breakers.
5-year limited warranty (elements excluded)
The HUUM HIVE 15 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, operating without the required UKU Extension Box, use of incorrect or non-approved stones, operating without the required stone load, or failure to follow HUUM's installation and operating guidelines. A licensed electrician is required. Do not connect to GFI/GFCI breakers. Two separate 50A circuits required. Proof of purchase from an authorized HUUM dealer is required. We are an authorized HUUM dealer.
