It's a floor-standing electric sauna heater designed to be built into your bench rather than stood beside it. It comes in a range of exteriors — black metal, stainless steel, and wood inlays in alder, aspen and thermo-aspen — so it can either stand out or disappear into the room entirely.

Rooms from 177 to 318 cubic feet. That covers most typical home saunas comfortably.

Length × width × height in feet. A 6' × 6' room with a 7' ceiling is 252 cubic feet, right in the middle of this heater's range. If you're near either end of the band, send us your dimensions and we'll check it properly.

Yes. Glass sheds heat faster than insulated timber, so a glass-fronted room behaves like a larger one. Tell us your glass area before you order and we'll size against it rather than raw volume.

It can be completely embedded into a sauna bench. Most heaters are objects in the room; the CORE can be built in so only the stone column is visible. That's a genuinely different design proposition, and it's why the finish options matter.

The heater sits within the bench structure rather than free-standing on the floor beside it. Done well, the result looks like a stone column rising out of the seating rather than an appliance in the corner. It requires planning at the carpentry stage — this isn't something you retrofit.

No. It works perfectly well as a free-standing floor heater, and comes with four adjustable legs for exactly that. Embedding is an option, not a requirement.

Talk to us and your carpenter before the bench is built. Clearances, access for stone loading, and the opening dimensions all have to be right the first time. Tell us at the design stage and we'll get you the installation manual so your builder works from real figures.

Black metal, and then combinations of a black or stainless steel frame with a naked, alder, aspen or thermo-aspen inlay. That's nine variations in total on this output — see the options on this page for what's currently available.

Appearance rather than performance. Alder is warm and reddish, aspen pale and bright, thermo-aspen darker and richer from heat treatment. All three are traditional sauna woods. Choose to match your bench timber, or deliberately contrast it.

No. Same heater, same output, same room range, same stone capacity across every finish. The difference is purely how it looks in your room.

If the heater will be visible, match or contrast your bench wood deliberately. If it's being embedded, the frame finish matters more than the inlay. Send us a photo of your sauna interior and we'll tell you what tends to work.

Yes, and this is not optional. Every HUUM heater requires a UKU controller, sold separately. There is no built-in control version — a CORE without a UKU simply won't run.

The UKU Local for straightforward digital control at the wall, or the UKU Wi-Fi if you want app control and scheduling from your phone. There are also Glass, Mirror and Gold finishes. Tell us how you'll use the sauna and we'll recommend one.

No. That's only required for heaters 12 kW and above. A 6.5 kW heater runs on the UKU controller alone.

240V single phase, drawing 25 amps. It's hardwired — no plug.

Yes. At 25 amps it's the lightest electrical load in the CORE range — the 9 kW draws 37.5 and the 10.5 kW draws 43.75. If your panel is close to capacity, that's a genuine saving on the installation.

Possibly, if you're replacing a 6 kW heater — 25 amps is the same draw as most 6 kW units. Send us a photo of your breaker and the old heater's rating plate and we'll confirm before you spend anything.

Yes, any licensed electrician can. Give them the manual and the load figures before they quote rather than after — and if you're embedding it, coordinate the electrical run with the carpentry before anything is built.

15.2" wide × 15.2" deep × 32.7" high (38.5 × 38.5 × 83 cm) — the CORE shares one body across the range, so the 6.5 kW takes exactly as much space as the 10.5 kW.

41.9 lbs empty. With 66 lbs of stones it's around 108 lbs, so whatever it stands on or is built into needs to carry that.

On the floor, with four adjustable legs supplied — or embedded into the bench structure. It's not a wall-mounted heater.

Levelling on an uneven sauna floor, and setting the height correctly if you're integrating it with a bench. They come in the box.

Minimum clearances to walls, benches and ceiling are in the installation manual and they're a fire-safety requirement, not a suggestion. If you're embedding it, these figures become the design constraint for your carpenter — get them before the bench is built.

No. The CORE takes 66 lbs of stones — two boxes of 5–10 cm stones at 33 lbs each — ordered separately. The heater won't run safely without them.

The CORE specifies 5–10 cm stones where the CLIFF takes 1"–2" (3–5 cm). Different geometry, different requirement. Check the model before you order stones — they aren't interchangeable across the HUUM range.

Because they share one body. The kW rating determines how large a room it heats; the 66 lb stone mass is the same throughout the CORE range and gives the same heat character regardless of output.

Only proper sauna stones in the specified size. Never river rock, granite, or decorative landscape stone — ordinary rock can crack or explode when water hits it at temperature.

Rinse them first, then stack loosely so air moves freely between them — never wedged tight or forced around the elements. The manual shows the correct arrangement.

Worth thinking about at the design stage. The stone column stays accessible from above in a properly planned installation, but access is exactly the sort of thing that gets designed out by accident. Raise it with your carpenter before the bench is built.

Inspect them once a year. They break down with repeated heating and cooling, and crumbling stones choke airflow through the heater. Restack as they settle, replace when they start falling apart.

The stones sit directly against the heating elements rather than being separated by a shield. Heat transfers into the stone mass more efficiently, which is what gives the heater its steam response when you ladle water.

Ask us to confirm the maximum setting for this model. Across the HUUM range heaters run to Finnish temperatures, and most people sit between 70 and 85°C in practice.

With 66 lbs of stone it charges faster than the CLIFF's 165 lbs, though a 6.5 kW takes longer than the larger COREs to move the same stone mass. Exact timing depends on your room size, insulation and starting temperature.

Yes — that's the point of a traditional heater. Ladle water over the stones for löyly. Plain water, a ladleful at a time, never poured directly onto the elements.

Only products made for sauna use, diluted in the water bucket rather than poured neat on the stones. Undiluted oils can scorch, stain the stones, and in some cases ignite.

Black steel or stainless steel casing depending on finish, with stainless steel industrial-quality heating elements. Wood inlays where specified.

Yes — alder, aspen and thermo-aspen are all traditional sauna woods chosen precisely because they cope with heat and humidity. Thermo-aspen is heat-treated for extra stability.

Yes — HUUM stock replacement elements as service parts. Worth knowing, because elements are excluded from the warranty as a wear item.

The heater, four adjustable legs, the installation and operation manual, and the warranty. Stones and the UKU controller are separate.

Three years limited residential, and one year limited commercial — both excluding the heating elements, which are treated as a wear item. Ask us for the current written terms before you order.

Heating elements are consumable in any sauna heater, like stones. HUUM stock them as service parts, and how long yours last depends heavily on whether you keep the stones properly stacked — packed-tight stones are the main cause of early element failure.

Yes — it carries a one-year commercial warranty. If it's going into a gym, spa or hotel, tell us; we handle commercial projects regularly and there may be considerations around duty cycle worth discussing.

The IDM lists a CE mark. Ask us to confirm the current North American listing before you order and we'll send it in writing — your electrical inspector will want documentation, and this is worth having on paper rather than taking on trust.

Designed, engineered and manufactured in Estonia.

One step up, covering 283 to 460 cubic feet against this one's 177 to 318, and drawing 37.5 amps against 25. Same body, same stone capacity, same finish options. There's overlap between 283 and 318 cubic feet — in that band either works, and the 6.5 kW is cheaper to buy and considerably lighter on the circuit.

Similar output, very different heaters. The CLIFF is tall, slim, carries 165 lbs of stone for a longer milder heat, and has exceptionally tight clearances. The CORE is squarer, carries 66 lbs, can be built into your bench, and costs less — both as a heater and because it needs two boxes of stone rather than five.

Neither. The CLIFF is the choice if you want maximum stone mass and the softest heat, or if clearances are tight. The CORE is the choice if you want the heater integrated into the room's design, and it's meaningfully cheaper all-in. They're built for different priorities.

No. Oversizing means a bigger circuit, a bigger installation cost, and a sauna that short-cycles and never develops proper steam. Size to the room.

By LTL freight rather than parcel. That means a delivery appointment and a truck at kerbside rather than a courier at the door. Tell us about your access and we'll sort the details with you.

HUUM's supplier lead time runs around 40 days, so this isn't a stock item you'll have next week. If you're building benches around it, order early — and tell us your deadline so we can be straight about whether it's achievable.

Wipe the casing occasionally, check and restack the stones annually, keep debris from building up around the unit, and let the room air out after each session.

Call us. We handle warranty claims directly with HUUM rather than handing you a phone number, and service parts including elements are available.

Because a working installation is the heater, a UKU controller, 66 lbs of stone and an electrical job — and the finish you choose affects the price. Freight varies by address and this ships LTL. Request pricing and you'll get one delivered figure for the complete setup.

We're an authorized HUUM dealer. On a heater designed to be built into your bench, getting the clearances and access right before the carpentry happens is worth far more than a slightly cheaper box — and that's a conversation, not a checkout.