iHKA Sauna Owner's Care Guide: Maintenance, Cleaning & Seasonal Care

The most important habits are the simplest ones. After every sauna session, take five minutes to do the following. This single routine prevents most long-term problems with the wood and benches.

After every session

• Open the door and any vents fully so the cabin can air out and dry.
• Wipe up any pooled water or sweat from the benches and floor with a clean cloth.
• Leave the door slightly ajar for at least one to two hours to allow the interior to dry completely.
• If you used the electric heater, switch it off and confirm the timer has ended.
• If you used the IKI wood stove, allow it to burn down completely and close the damper only once the ashes are cool.

2. Weekly cleaning

With regular use (one or more sessions per week), give the cabin a light clean once a week.

Interior wood and benches

• Sweep or vacuum loose debris from the floor and bench slats.
• Wipe benches, headrests and the upper bench supports with a damp (not wet) cloth and warm water. Clean water is sufficient for normal use.
• For visible stains, sweat marks or discolouration, use a soft brush with warm water and a small amount of a mild, neutral, fragrance-free soap. Rinse with a clean damp cloth and dry.
• Air the cabin fully afterwards with the door open.

Glass door

• Clean the inside of the glass with warm water and a microfibre cloth. For mineral haze, a small amount of white vinegar diluted in water works well.
• Avoid ammonia-based glass cleaners on the inside surface, as residues can affect the air inside the sauna.

Floor

• Lift any duckboards or floor grids if fitted, sweep underneath, and let everything dry before replacing.

3. Quarterly tasks

Every three to four months, set aside an hour for a more thorough check. Do this with the sauna fully cool and the power off.

• Inspect all visible wood surfaces — walls, ceiling, benches, door frame — for any cracks, loose boards or splinters. Light surface checking is normal as wood expands and contracts; loose fixings should be tightened.
• Sand any rough spots on benches, headrests or backrests lightly with fine grit (180–240) sandpaper, in the direction of the grain. This restores the smooth feel and removes minor sweat marks.
• Vacuum the air intake and exhaust vents to keep the airflow system working as designed.
• Check the door hinges and handle: tighten any loose screws, and apply a tiny amount of high-temperature suitable lubricant to hinges only if they begin to squeak.
• Inspect the area around the heater for any signs of scorching, discolouration or melted material. If you see any, stop using the heater and contact us.
• Check the exterior for any damaged seals, missing fasteners, or signs of water ingress around the roof, door or chimney penetration.

4. Annual deep maintenance

Once a year — a quiet weekend in spring or autumn is ideal — give your sauna a full service.

Interior

• Remove duckboards, loose benches and headrests. Take them outside if possible.
• Sand bench surfaces lightly with 180-grit sandpaper, then 240-grit, in the direction of the grain. Wipe down with a barely damp cloth and let dry fully.
• Inspect the underside of benches, the floor area beneath them, and the lower wall sections — these are the spots where moisture lingers longest.
• Vacuum thoroughly, including all corners and the heater guard area.

Heater

See sections 8 and 9 for the full annual heater service. The yearly stone check is the most important task.

Exterior

See section 6 for guidance on inspecting the exterior cladding and finish.

5. Caring for the interior wood

Your sauna interior is finished in untreated Finnish spruce, pine or aspen. Sauna wood is deliberately left untreated: it must be free to absorb and release moisture with each session. Sealing or varnishing the interior would trap moisture, cause peeling at high temperatures, and release fumes.

Do

• Use a bench cover, towel or seat pad whenever you bathe. This is the single most effective way to keep benches clean.
• Wipe spilled water or oil immediately.
• Sand lightly when surfaces become rough or marked.
• If you wish to refresh the wood, plain warm water is almost always enough. For stubborn marks, dedicated sauna-wood cleaners (sold by reputable Finnish sauna suppliers) are available — follow the product instructions exactly.

Do not

• Do not apply varnish, lacquer, oil or wax to the interior walls, ceiling or the bathing surface of benches.
• Do not use household cleaning sprays, fragranced cleaners or bleach.
• Do not steam-clean or pressure-wash the interior.

6. Caring for the exterior

The exterior cladding of your iHKA Sauna is finished in your chosen colour. Unlike the interior, the exterior is exposed to weather and benefits from periodic protective treatment.

Quarterly

• Rinse the cladding with clean water from a garden hose to remove dust, pollen and bird droppings. Avoid pressure washers.
• Inspect the roof and the chimney penetration (if you have the IKI wood stove) for any leaves, debris or moss. Clear gently.
• Check the base and the area around the door for water pooling or blocked drainage.

Annually

• Inspect the exterior finish for any cracking, peeling or fading, particularly on the south- and west-facing sides which receive the most sun.
• Touch up small areas of damage promptly to prevent water reaching the wood beneath.
• Recoat the exterior with a suitable exterior wood treatment when the surface starts to look dry or the colour is fading. The interval depends on your local climate, sun exposure and the original finish; for most installations in Belgium and the Netherlands, plan to recoat every two to four years.

7. Sauna stones

The stones are the heart of your sauna. They store heat and convert poured water into löyly, the soft and powerful steam that defines the Finnish sauna experience. Stones are also a wear part: they break down gradually under the repeated cycle of heating, water and cooling.

What to look for

• Cracks, splits or visible flaking on the surface of stones.
• Small fragments and dust accumulating at the base of the heater.
• Stones that have settled noticeably, leaving heating elements or the IKI fire pipe more exposed.
• A noticeable drop in steam quality — weaker or shorter-lived löyly than when the sauna was new.

Annual stone check

Both Harvia and IKI publish the same core guidance: rearrange the stones at least once per year, more often with frequent use. Remove broken pieces and replace any disintegrated stones.

• Make sure the heater is fully cold and the power is off.
• Wearing gloves, lift the stones out one by one and lay them on a clean cloth.
• Discard any stones that are cracked, flaking or noticeably reduced in size. Sweep out any fragments and dust from the base of the heater.
• Inspect the heating elements (Harvia) or fire pipe and mesh (IKI) for damage. If anything looks scorched, deformed or out of place, stop and contact us.
• Repile the stones loosely, leaving small gaps between them so air can circulate freely. Do not pack stones tightly.
• Top up with new stones of the same type and size as needed.

Replacement stones

Use only proper sauna stones — typically peridotite, olivine diabase or olivine, sized between 5 and 10 cm. These materials can withstand the repeated thermal shock of löyly. Do not use river stones, decorative stones, or any stone not sold specifically as a sauna stone: they can crack violently when water is poured.

In intensive use (commercial-style frequency), a full stone replacement once a year is recommended. For typical private use, replace stones gradually as they break down, and plan a full refresh every three to five years.

8. Electric heater — Harvia Cilindro

If your sauna is fitted with the Harvia Cilindro electric heater, please follow the manufacturer’s manual that was supplied with the heater. The points below summarise the key owner-facing maintenance tasks. Do not attempt internal electrical service yourself: this must be done by a qualified electrician.

Before each session

• Check that nothing has been placed on top of the heater or within the safety distance.
• Confirm the stones are well distributed and that no heating element is exposed.

Cleaning the heater body

• Switch off and unplug the heater. Allow it to cool fully.
• Wipe the exterior with a soft, dry cloth to remove dust.
• Do not use abrasive cleaners or solvents on the heater body.

Annually

• Carry out the full stone check described in section 7.
• Have a qualified electrician inspect the connections and check for any damage to the cabling, particularly if you have noticed any change in heating performance.

First use after a long pause

• On first heating after a long winter or extended unused period, the heater and stones may briefly emit a smell as residual moisture and dust burn off. Ventilate the sauna well during this first heat. This is normal.

9. Wood-fired stove — Mini IKI

If your sauna is fitted with the Mini IKI wood-burning stove, please follow the manufacturer’s instructions supplied with the stove. The points below summarise the key owner-facing tasks.

Before each fire

• Clean ashes and any unburnt remnants from the firebox.
• Open the chimney damper, the air control on the stove door, and the ash box damper to allow maximum airflow at lighting.
• Load no more than two-thirds of the firebox height with dry, seasoned firewood. Larger pieces underneath, smaller pieces on top, light from the top.
• Use only dry firewood. Wet or unseasoned wood produces poor heat, heavy smoke and excessive creosote.

After each fire

• Allow the fire to burn down fully. Close the damper only once the ashes are cool to the touch.
• Once cool, scoop the ashes into a metal bucket and store outside the sauna.

Chimney sweeping

Chimney sweeping is a safety-critical task. Follow IKI’s guidance and your local fire-rescue regulations.

• In private holiday or recreational use, sweep the chimney every three years.
• In private regular use, or any commercially used or year-round shared sauna, sweep the chimney every year.
• Use a flexible nylon brush — never a metal brush, which damages the inside of the pipe. An industrial vacuum is an acceptable alternative for the spiral section.
• To access the chimney, remove the stones first, then open the cleaning hatch on the chimney pipe; no tools are required for the hatch itself.
• In Belgium, chimney sweeping by a registered specialist is required by regional regulation. We strongly recommend using a certified chimney sweep — it is also normally a condition of household insurance.

Stove body and paint

• The hatch may change colour or the paint may wear with time — this is normal.
• If you wish to refresh it, sand and clean the hatch with a degreaser, then repaint using a heat-resistant paint rated for at least 600°C.

10. Seasonal checklist

A quick reference. Tear out, photograph, or pin to the inside of your storage cupboard.

11. What not to do

A short list of things that cause more damage than any other single cause. Avoiding these will keep your sauna in beautiful condition for a very long time.

• Do not seal, varnish, oil or wax the interior wood.
• Do not use a pressure washer on the sauna, inside or out.
• Do not use bleach, ammonia, or any strongly scented household cleaner inside the cabin.
• Do not pour sea water or salty water on the stones — this voids the heater warranty.
• Do not use river stones, decorative stones or anything not sold as a sauna stone.
• Do not hang clothing or towels on the heater or use the sauna to dry laundry.
• Do not operate the sauna with the heater obstructed or with stones missing.
• Do not carry out electrical service on the Harvia heater yourself.
• Do not burn rubbish, painted wood, treated timber or excessive volumes of cardboard in the IKI wood stove.
• Do not close the chimney damper while embers are still hot.
• Do not store firewood, cleaning products or any flammable item inside the safety distance of the heater.

12. Troubleshooting common issues

The wood is darkening unevenly

Almost always a moisture issue. Check that you are airing fully after each session, that vents are not obstructed, and that water is not pooling on benches or floor. Light sanding can refresh marked areas.

There is a musty smell when I open the door

Ventilation is insufficient or the cabin has not been drying fully between uses. Leave the door open for several hours after every session. Run an empty heating cycle with the door slightly ajar to dry the cabin out, then air thoroughly.

The löyly is weaker than it used to be

Most often the stones have settled or broken down and need rearranging or replacing. Carry out the annual stone check (section 7). Also confirm you are using a sensible amount of water; over-watering cools the stones.

The Harvia heater stops heating mid-session

Check the manual’s troubleshooting section first. The overheat protector may have triggered — most often because stones have settled and exposed an element, or the temperature sensor is not correctly installed. Allow the heater to cool, address the cause, and reset per the manual. If the issue persists, do not continue to use the heater — contact us.

The Mini IKI is smoking back into the room

Check that the chimney damper and air controls are fully open at lighting. The chimney may need sweeping. Confirm the cabin has sufficient compensation air — a wood stove needs incoming air to draft properly. If smoking persists, stop using the stove and have the chimney inspected by a certified sweep before next use.

Visible dripping or staining on the exterior cladding

Inspect the roof, the chimney penetration (if applicable) and the seals around the door. Catch and fix small issues quickly — water that finds its way behind the cladding can cause significant hidden damage.

13. Service, support and warranty

We are here for the full life of your sauna. If you have any question — from a small wood scuff to a heater concern — reach out before you act. Most issues are simple to resolve when caught early.

Contact

Mats Verbrugge — Belgian distribution lead

Email: mats.verbrugge@ihkasauna.fi

Phone: +32 472 02 49 03

Showroom: Treurenborg 9, 2030 Antwerpen, Belgium

Web: ihkasauna.fi

Production and technical contact

Toni Rummukainen — iHKA Sauna, Masku, Finland

Phone: +358 45 667 3484

References and sources

The heater-specific guidance in sections 8 and 9 of this guide is drawn from the official manufacturer documentation:

• Harvia Cilindro user manual — stone rearrangement, exterior cleaning, troubleshooting.
• IKI Mini wood-burning stove instruction manual — firing, ash handling, stove body care.
• IKI installation and use guide — chimney sweeping intervals, löyly water guidance, sauna stone selection.

In case of any conflict between this guide and the official manuals supplied with your heater, the manufacturer’s manual takes precedence. Please retain those manuals alongside this document.

A note on warranty

Following the maintenance guidance in this document, and the manufacturer’s instructions for your heater, is a condition of the warranty cover on your sauna and its components. We recommend keeping a simple maintenance log and retaining proof of purchase. If you sell or move your sauna, please pass this document and the heater manuals on to the new owner.

Thank you for being part of the iHKA Sauna family.

Hyvät löylyt — enjoy your sauna.

Handcrafted in Masku, Finland

ihkasauna.fi