EOS Mythos S35 7.5 kW Electric Sauna Heater

The EOS Mythos S35 7.5 kW is a floor-standing electric sauna heater rated at 7.5 kW, for rooms of 45.2-67.8 sq ft at a 6.2 ft ceiling (about 280-420 cu ft). Available on 208V 3Ph or 240V 2Ph, in anthracite, black, stainless steel trim or white. The Cubius stone set is included; natural stones are not. It ships without controls and takes an EOS Touch 3 or EmoTec D control, sold separately.

Mythos S35 is a tall, narrow tower, 33.1 in high on a 16.5 × 14.6 in footprint, in an angular all-steel construction only 14.6 in deep. The rock store sits on top and stays open for maintenance, and EOS's cube-shaped Cubius stones, colour-matched to the cabinet, sit above the working fill.

These are not included. You need them before the sauna will run.

Figures are from EOS's North America installation manual and datasheet for this heater. Breaker and conductor sizing remains your electrician's call under the NEC and local code.

The minimum distances EOS publishes for this heater. Measure before you frame the bench.

EOS states a heater guard rail is essential on this model so the heater cannot be touched. It is sold separately. These are minimums to combustible material, not recommendations. The installation manual and your local code take precedence.

This page is the 7.5 kW Mythos S35. EOS rates it for 45.2-67.8 sq ft of floor area at a 6.2 ft ceiling, about 280-420 cu ft.

EOS sizes its heaters by floor area at a 1.90 m / 6.2 ft ceiling rather than by volume. Measure your floor, then add allowance for anything that absorbs heat instead of reflecting it, glass, tile, concrete, stone and exposed log all make a room behave larger than it measures. If you fall between two outputs, size up.

Other outputs in the Mythos S35 range

Work out your room with the sauna heater size calculator

• EOS heaters ship without controls. The control mounts outside the hot room and switches the heater through a separate power box.
• Mount to the clearances published above.
• The cabin needs an air inlet and outlet of at least 35 x 5 cm (13.8 x 2 in), and an air exchange of five times the cabin volume per hour.
• Hardwired on a dedicated circuit by a licensed electrician. EOS specifies a fuse of 30 A on 208V 3Ph; 20 A on 240V 2Ph, on copper conductors rated for at least 90 °C.
• Stones are not supplied. Load them loosely by hand so air moves between them, and never run the heater with an empty rock store.

EOS's North America documents for this heater. The manual carries the wiring table, the clearance diagrams and the air inlet sizes. The control is a separate product and its manual is on its own page.

• Installation and operating instructions (Mythos S35 and S45) (PDF)
• Datasheet (PDF)

What size room does the 7.5 kW EOS Mythos S35 heat?

EOS rates this output for 45.2-67.8 sq ft of floor area at a 6.2 ft ceiling, which works out to roughly 280-420 cu ft. EOS sizes by floor area rather than volume. Add allowance for glass, tile, stone or concrete, and size up if you fall between two outputs.

What circuit does the 7.5 kW EOS Mythos S35 need?

A dedicated circuit on the supply you choose. EOS specifies a fuse of 30 A on 208V 3Ph; 20 A on 240V 2Ph, on copper conductors rated for at least 90 °C. Your electrician sizes the breaker and conductors to the installation manual, the NEC and local code.

Which control does the EOS Mythos S35 need?

Either an EOS Touch 3 or an EOS EmoTec D/H (USA/CAN), EOS's North America datasheet lists both for this heater, and its installation manual names the EmoTec D/H. The heater cannot run without one. The control mounts outside the hot room, which is what lets you bring the sauna up to temperature before you walk in, and it switches the heater through a separate power box.

Are stones included with the EOS Mythos S35?

Partly. The colour-matched Cubius stone set ships with the heater and is the layer you see from the bench. The natural sauna stones underneath it are not included: EOS lists them under optional accessories in its North America manual. The rock store takes 35 kg / 77 lbs at a 100-150 mm (4-6 in) caliber, coarser than the fill most heaters at this size use. The natural stones go in first, up to the top edge of the inner rock store, then the Cubius frame sits on that edge. You can add boxes on this page.

Is the EOS Mythos S35 UL listed?

EOS publishes no UL, ETL or CSA listing for its heaters. Its North America manual requires UL 875 labelling and states that the temperatures settable from the control are tested to UL 875 or CSA C22.2#60335-1:2016 Ed.2 and CAN/CSA E60335-2-53, which is not the same as a listing. Some jurisdictions and insurers require a listed appliance, so confirm before you buy.