The wood burning sauna stove is the heart of the traditional sauna – and perhaps the most important decision you’ll make designing yours. There are many strong opinions, and a lot to consider when choosing the best wood burning sauna stove.
The perfect burn requires the right amount of air flow and proper draft control for the different stages of the fire.
The stove and chimney must be designed with high quality metals that can withstand years of heat and moisture. Very heavy, thick metal stoves provide the most consistent heat and will last longer, but light weight will heat up faster and is better for mobile saunas.
The size and design of the sauna stove will determine the quality of the burn. Companies like Lamppa Kuuma have made an art out of it.
An inefficient burn will cost you money and time, it can take twice as much wood to heat up to your desired sauna temperature.
The quality of your wood burning sauna stove also impacts your neighbors and the environment. An efficient burn causes more fine particulate emissions and black smoke from the chimney stack. A quality stove with an efficient burn will have clear smoke that your neighbors won’t even notice.
Here are the best wood burning sauna heaters that will give you the most efficient burn, quality of heat, and value.
The Harvia M3 is the most popular wood burning sauna heater in Finland, where they are made. It’s also the most widely available wood burning sauna heaters in the world, by a company with a 60+ year track record.
Does that make it the best wood burning sauna heater?
Maybe not, but that makes it a contender on anyones list of best wood sauna stoves.
The M3 is also the most imitated sauna stove on the market, with the Polar KS20 and Nature NTSW-CYA (both listed below) bearing a striking resemblance.
Wood burning stoves can be dangerous, and many people just want the most popular heater because they understandably think its the safest.
Note: the Harvia M3 is often sold as the Catalina M3 in North America. Just like electric sauna heaters, this is mostly a case of a couple dominant brands (Harvia and TyloHelo) selling their products to other sauna companies to sell as their own.
The Harvia M3 has a optional water heating tank that fits between the woodstove and the chimney pipe. This heats up water very quickly as the pipe essentially goes through the water tank itself.
This is the easiest way to heat water for showers while adding thermal mass to your sauna. You can buy it here.
The extra thermal mass is recommended for the M3 because it is relatively lightweight. The benefit is that is heats up faster, but most people prefer the heat when there’s more thermal mass.
The M3 also has a glass door, which lets the glow from the fire set the ambiance in the room.
In short, the Harvia M3 is great for small to medium saunas 6-13 cubic meters. It’s very popular in small outdoor saunas and barrel saunas including Almost Heaven Barrel Saunas that were sold at Costco.
The compact, relatively lightweight M3 is also a popular choice for mobile saunas.
Here’s What Some People Don’t Like About The M3:
- Not enough room for sauna rocks
- Takes a maximum length of 15.25″ firewood, when standard is often 16″
- 5/32″ steel thickness, many prefer up to 1/4″
- Looks too modern-looking
Here’s What’s Reviews Say About The Harvia M3:
- Great airflow through the rock tray
- Easy to light and maintain fire
- Clean and efficient
- Löyly is great, especially with large stones
- UL and CE Approved
- Width: 390mm
- Height: 710mm
- Depth 430mm
- Weight: 45 KG
- 30 KG Stone Capacity
- Heater Output: 16.5 kW
- See clearances here.
Other Harvia Models
Harvia has a very large range (20+) of wood sauna heaters of all practical size for both home and commercial use. There are eight Harvia Wood Burning Stove models that are readily available in the US, they can be found here. The M3 is the smaller of the models, and the Harvia 36 (AKA Catalina 36) is the largest for big saunas up to 120 square feet.
Small: Up to 512 cubic feet
Medium: Up to 800 cubic feet
Large: Big saunas over 800 cubic feet
Kuuma wood burning stoves are built like bank bank vaults and have a cult-like following. They have 1/4″ reinforced steel and probably the best welding on the market.
The Kuuma wood stoves have a precise air control system that gives the operator complete control of the burn.
The most impressive thing about the Kuuma is how little fuel it consumes and how quickly it heats up a sauna. It takes one load of wood as little as 30 minutes to reach sauna temperatures.
Additional options available include a hot water coil, hot water tank (12 or 16 gallons), integrated heat shields, glass window, optional ash pan, and a through wall throat extension for outside feed sauna stove.
Feeding wood from the outside will reduce ash inside the sauna and may be better if you want to build a more air-tight sauna. It also allows you to keep wood outside the sauna room.
The small and medium models accept standard 16″ logs while the large model can handle 24″ stock.
The optional hot water tanks will allow you to heat water for bathing, and provide additional thermal mass. The attach to either side of the stove.
Speaking of thermal mass, the Kumma stoves alone weigh in between 375-455 pounds before placing rocks. These stoves are so powerful they’ll keep your sauna hot for hours after the fire is out.
Kuuma has a long history and many users boasting 20+ years of reliable use.
If you’ve ever listened to the podcast Sauna Talk or read Sauna Times, you know Glen over there is a big fan of Kuuma stoves. You can listen to his interview with Daryl Lamppa here. Daryl is a third generation stove builder and currently runs the business.
Lamppa Kuuma sells directly to customers from their website, they run between $1000 and $1500 without add-ons. .
Here’s What Some People Don’t Like About The Kuuma:
- Slightly more complicated than the M3, geared towards advanced sauna users who like to have full control of fire.
- All parts get extremely hot, fire gloves are recommended.
- These stoves get so hot, even pouring water on the rocks should be done carefully to avoid scalding.
- You may want to repaint the door with high temperature paint to keep it looking great.
Here’s What’s Reviews Say About The Kuuma:
- “It’s like loading wood into a tank”
- Incredibly efficient burn – starts with little smoke and turns into no smoke at all.
- “You’ll be amazed how little wood you need with a Kuuma”
- Requires half the wood that other stoves need for the same heat.
- Great design, “in 3 years I’ve never seen a spark come out of the chimney”.
- “Love the front to back burn, keep hot coals towards the door and put new wood in back.”
- Looks incredible, well worth the money.
- “Excellent customer service and sauna stove”
- UL #1482 Approved
- Air Tight
- Manual here.
- Baffled and Brick-Lined Combustion Chamber
- Unique Front-To-Back Burn
Nippa is a classic sauna heater company that’s been building almost the same heaters since 1930 in Beulah, Michigan.
Like Kuuma stoves, these have an armored feel to them and look like they will outlast humans on this planet.
The base model has a base price around $1000 with optional heat shields, rocks, and an integrated hot water tank that holds 6 gallons of water on the side or rear of the stove.
You can also order any Nippa stove with outside-fire extensions if you want to feed your stove from outside the steam room.
The WB-18 weighs 230 pounds and can fit 17″ logs.
Like Harvia and Kuuma stoves, Nippa has users brag of using their stoves for 20+ years.
Here are some Reviews of the Nippa Stoves:
- Gets the job done in righteous fashion.
This is a cheaper version of the Harvia M3. If money is tight, this will save you $300-400 USD and will get the job done.
Rest assured, it’s made with heavy gauge steel and comes with a two year warranty, which is actually better than the one year warranty you get with a Harvia M3.
There is a rock capacity of 54-72 pounds, compared to a max 66 pound capacity by the M3.
Like the M3, the Nature NTSW has an ash tray for easy removal, a heavy duty cast iron grate, and is a great choice for small or medium outdoor sauna or barrel sauna.
The Hanko KS20 is a comparable to the Harvia M3, and is made for sauna 282-706 cubic feet. It is white labeled for sale in North America by Polar, and originally manufactured by Tylo. This type of relabeling is common in sauna both electric and wood burning sauna heaters.
The KS20 comes standard with a glass door to see the glow of the fire. The front panel also has a very sleek satin steel finish that should last a lifetime.
The KS20 has a patented ‘Coanda’ air circulation system for fast heat up and good air flow through the large rock tray.
It includes 132 pounds of Finnish sauna stones. At $1200+ price range, you will get more value from similar Harvia models.
Polar also has an external feed model, the 20SL and the 16k basic heater both available in US and Canada.
Outdoor and Sauna Tent Heater
The Guide Gear Outdoor wood stove is a great way to save money if you’re building a DIY outdoor sauna, or a temporary sauna tent where you’re not necessarily looking for a lifelong solution.
You will have to get a little creative with coming up with a rock basket, but even stacking a metal bucket full of rocks on top will get the job done.
List To Review: Misa, Narvi, Spartan, Stoveman, Saunacore Country Living 24
Tips for the best wood burning sauna heater results
- Never operate a wood burning stove in a room that is too air tight. Proper fresh air intake is essential for combustion.
- Always try to burn dry wood, as wet or “green” wood promotes creosote buildup in chimney.
- Consider breaking it in outdoors before the first use. Most wood sauna stoves, including the M3 give off a strong gassy odor for the first few burns. Leave the door open and let it burn out, do not breathe it in or use the sauna until the smell goes away. Some wood sauna heaters, like the Harvia M3 recommend using without rocks the first few times, and placing rocks only after cooling off.
- Pack rocks loose and random, it’s essential to have good airflow through the rocks. If top rocks don’t get hot, it’s probably too tightly packed.
- Rinse them first to remove dust gained in transport
- Save the smallest rocks for the top of the stove.
- Make sure you choose a sauna heater for your room size: too small and you will drive your sauna too hard and reduce its life.
How To Operate a Wood Burning Sauna Stove
Even with the best wood burning stove, you will not have an efficient burn with bad technique. You will learn to appreciate the subtle changes in the burn and how to move it through different stages. This is part of the joy of wood burning saunas, and you will get better and enjoy it more with.
If you let too much wood in, you will have a fast burn which not only wastes fuel but can overheat your stove and even cause a chimney fire.
Fire needs air to burn. Start your sauna fire with the draft all the way open. Now you need to find out if your draft completely closes or not.
Most draft controls don’t close completely, and are best operated turned all the way to the ‘closed’ position after the fire is burning.
If closing it all the way puts out the fire, or you see smoke coming back down from the chimney stack, you have a sealed stove. You’ll need to have it slightly open at all times.
For most sauna stoves, it’s OK to have the draft control completely closed as they are not sealed.
Keeping the draft closed after getting going will allow the wood to fully burn, maintain more heat, conserve fuel, and prevent overheating.
Before opening your stove door, open the draft first to prevent ashes and smoke from getting in the sauna.
Wood Burning Safety and Sauna Fires
What You’ll Need To Install a Wood Burning Sauna Stove
Wood Stoves will require some basic tools for installation. Make sure to refer to your manufacturers manual, but you can save some time by having these tools ready before it comes.
- Small Tape Measure
- Screw Gun (or Cordless Drill)
- Cutting Tool
- Reciprocating Saw
- Vice Grips
- Step Ladder
- A Helper
Sauna Wood Stove Considerations
Your wood stove and exhaust system need regular maintenance, depending on how often you use it, and the quality of wood. Read instructions for your stove for manufacturers recommendations.
Sauna builders should also follow local code and installation instructions for all clearances between stove and combustable materials. Not following these guidelines is dangerous and can result in a dangerous fire.
Sizing your wood burning sauna is also a tricky matter that involves climate, sauna insulation, sauna air tightness, and user preferences.
Oversizing your sauna heater is not necessarily an issue if you have plenty of thermal mass and sauna rocks to spread the heat. More thermal mass will result in a more consistent sauna session that maintains heat long after the last log is fed.
Weight is a big consideration for mobile saunas, which need to have enough thermal mass for a traditional sauna but still be mobile and fit under weight restrictions. Mobile sauna stoves should be located in the center of the trailer whenever possible.