Recovery

How to Clean a Sauna Without Damaging the Wood or Heater

The short answer: let the sauna cool completely, switch off and isolate power as the manual directs, remove loose debris, then clean unfinished wood with a small amount of warm water and a sauna-approved mild cleaner. Use a soft brush along the grain, remove cleaner residue, and dry the room with ventilation and the manufacturer-approved drying cycle.

Traditional and infrared saunas are not cleaned exactly the same way. Never spray water onto a heater, control, sensor, infrared emitter, wiring opening, or fan. The cabin and heater manuals override general advice, especially for treated wood, glass coatings, electronics, and removable stones.

What You Need—and What to Leave Outside

  • A vacuum with a soft brush attachment or a dry hand brush
  • Two microfiber cloths
  • A soft natural- or nylon-bristle hand brush
  • A bucket with a modest amount of warm water
  • A sauna cleaner or mild detergent approved for the cabin material
  • Protective gloves and the sauna and heater manuals

Avoid pressure washers, steam cleaners, abrasive pads, paint, lacquer, household furniture polish, and unapproved bleach or solvent cleaners. Do not combine an acidic descaler with a chlorinated product. Harvia specifically warns against using its acidic heater cleanser with chlorinated substances.

Gloved hand cleaning an unfinished wooden sauna bench along the grain with a soft brush
Use limited water and brush unfinished benches along the grain while the heater is off and cool. Original illustrative image created for NYC Fitness.

How to Clean a Traditional Sauna

  1. Cool and power down. Wait until the heater and stones are completely cool. Switch off the heater and disconnect it at the breaker or other isolation point if the manual requires this for cleaning.
  2. Remove accessories. Take out towels, mats, buckets, headrests, and any removable floor grid. Launder textiles separately.
  3. Dry-clean first. Sweep or vacuum hair, dust, leaves, and grit from benches, under bench frames, corners, vents, and the floor. Keep the nozzle away from sensors and wiring.
  4. Clean from top to bottom. Wipe lightly soiled wall panels with a damp cloth. For unfinished benches, apply the approved diluted cleaner with a cloth or soft brush and work along the wood grain.
  5. Remove the residue. Use a clean damp cloth or the limited rinse method in the cabin manual. Do not flood joints or leave standing water beneath benches.
  6. Clean the floor and glass. Use products compatible with the specific tile, sealed floor, drain, and glass. Keep overspray off wood and electronics.
  7. Wipe the heater exterior only as directed. A cool heater exterior can generally be wiped with a damp cloth. Use a model-approved scale treatment only on compatible surfaces, never inside electrical openings.
  8. Dry completely. Replace removable parts only after they are dry. Open the designed vent and door as directed; use the heater drying cycle only if the manufacturer permits it.

Traditional vs. Infrared Sauna Cleaning

The surfaces that change the cleaning method
AreaTraditional electric saunaInfrared sauna
Heat sourceCool heater exterior and stones; follow heater manualEmitters, guards, fans, and controls stay dry unless the manual gives a damp-cloth method
WoodOften unfinished benches and paneling; use limited water and sauna-approved cleanerMay combine wood with fabric emitter covers or electronics; clean each material separately
MoistureSome cabins permit careful rinsing of benches and wet-room floorsUsually favor a well-wrung cloth; never assume the cabin can be rinsed
Stone careInspect, re-stack, clean, or replace only on the heater maker’s scheduleNormally no sauna stones unless it is a hybrid model
DryingVentilation and, where approved, a short heater-assisted drying periodVentilation with the unit off unless its manual provides another process

A Cleaning Schedule That Prevents Deep Scrubbing

Adjust the schedule for household size and use frequency
FrequencyTasks
After each sessionRemove towels and bucket, wipe sweat or water drops, clear plant material, and leave the sauna in its approved drying configuration
Weekly or every few sessionsSweep or vacuum the floor, wipe high-touch surfaces, wash accessories, and inspect for odor or damp areas
Every 1–4 monthsClean beneath removable grids and benches, wash glass and floor, inspect vents, fasteners, seals, and visible heater surfaces
One to three times per yearPerform a full cabin clean; Harvia gives this range for a family sauna, while some heater manuals call for a thorough wash at least every six months
At the heater’s intervalInspect or re-stack stones, remove debris, and replace crumbling stones according to the exact heater manual

Stains, Odor, and Suspected Mold

  • Sweat or water marks: use the approved cleaner and soft brush first. Aggressive sanding removes material and can create an uneven surface.
  • Dark surface marks: when the manufacturer permits it, lightly sand completely dry unfinished wood with the specified grit, working evenly with the grain.
  • Musty odor: clean and dry the cabin, then inspect under benches, floor grids, vents, wall penetrations, and the room around the sauna for trapped moisture.
  • Recurring growth, soft wood, or spreading discoloration: stop use and arrange a moisture and ventilation assessment. Surface cleaning will not solve a leak or hidden growth.

Do not cover stained or damp interior wood with paint, lacquer, or a household sealer. Harvia warns against lacquer on interior sauna surfaces and recommends only treatments made for the intended sauna wood.

Stop Cleaning and Arrange Service When

  • The heater, controller, sensor, cable, or infrared panel is cracked, scorched, loose, wet inside, or unusually discolored.
  • You smell burning, hear abnormal fan or electrical noise, or a breaker trips.
  • Bench supports move, fasteners protrude, glass is chipped, or a door does not close safely.
  • Stones are crumbling into the heater or the heater’s required clearances are obstructed.
  • Water has entered an electrical opening or standing water cannot drain.

Leave the sauna off and have the appropriate manufacturer-authorized technician, electrician, carpenter, or moisture professional inspect it.

Planning a new installation instead? Our home sauna cost guide covers the line items that are commonly missed.

Sources and Manufacturer Guidance

Requirements can vary by product, model, and situation. These primary sources informed this guide; official instructions for your exact product and current authoritative guidance take priority.

  1. Harvia: Maintaining Your Sauna
  2. Harvia: Five Sauna Maintenance Tips
  3. Harvia/Finlandia Heater Manual: Sauna Room Hygiene
  4. Saunum Installation and User Guide: Cleaning and Maintenance Boundaries

Frequently Asked Questions