18kW - 30kW

Heaters in this class are designed for large-scale commercial facilities or substantial luxury home suites.

• 18kW - 20kW: Typically suitable for rooms between 18 and 30 cubic metres.
• 24kW - 26kW: Designed for larger volumes of 24 to 40 cubic metres.
• 30kW: The most powerful standard electric option, capable of heating massive rooms up to 45–50 cubic metres.

Note: Commercial saunas often feature extensive glass walls. You must use our Sauna Heater Calculator to adjust for this, as a glass-fronted room will require significantly more power than a fully insulated timber cabin.

No. Heaters in the 18kW–30kW range require a 400V Three-Phase electrical supply (often referred to as "red phase" or industrial power).

• Amperage: An 18kW heater draws approximately 26 Amps per phase, while a 30kW unit can draw over 40 Amps per phase.
• Availability: Standard UK residential properties (single-phase 230V) cannot support these loads. If installing in a private residence, you will likely need a new three-phase connection installed by your Distribution Network Operator (DNO).

Please Note: It is the customer's responsibility to consult a qualified electrician to assess and install the suitable electrical requirements to the heater's specification.

At this power level, it is unsafe and impractical to run the full electrical load through a small digital control panel on the wall.

• The System: You will need a Contactor Box (Relay Unit). This heavy-duty box is usually installed in a plant room or ceiling void.
• How it works: Your sleek wall-mounted control panel sends a low-voltage signal to the Contactor Box. The Contactor Box then handles the heavy switching of the 400V mains power to the heater elements. This ensures safety and longevity for the control system.

Yes. Heaters in this bracket are engineered for "continuous duty."

• Construction: They typically feature reinforced chassis, larger stone capacities (often 50kg to 100kg+), and heavy-gauge industrial heating elements designed to withstand the rigours of 12+ hours of daily operation in gyms, hotels, and spas.
• Maintenance: For facilities running continuously, we recommend inspecting the stones monthly and replacing them every 3 to 6 months to prevent element failure caused by compacted stone dust.

Absolutely. In a large room with high occupancy (10+ people), passive natural ventilation is often insufficient.

• Mechanical Extraction: It is industry standard to install a mechanical extraction system to ensure 6 to 8 air changes per hour.
• Heater Performance: Proper ventilation is not just for hygiene; it ensures the heater's temperature sensor reads the room air correctly. Without good airflow, heat can "pool" at the ceiling, causing the heater to cut out while the benches remain cool.

• Supply to Contactor: You will need heavy-duty armoured cable (SWA) running from your distribution board to the Contactor Box.
• Contactor to Heater: You must use high-temperature Silicone Rubber (SiHF) cable for the final connection to the heater. Because the load is split across three phases, you typically use 5-core cable (L1, L2, L3, Neutral, Earth).
• Please Note: Always consult a commercial electrician to calculate the correct cable cross-section (mm²) based on the run length to prevent voltage drop.