Selecting the Right Sauna Stove (blog link)

Finished taking a sauna, now what?

We highly recommend the Bake and Breathe method (Blog) to keep your sauna stove and sauna in optimal condition.

How does the draft control operate?

The draft control should never be left in the high burn position for longer than 5-10 minutes to prevent overheating.  When the draft lever is left in a full-open position, you send all the heat right up the chimney, and it's not heating your hot room.  It will also severely overheat the stove.  To heat your hot room effectively, you want the draft about 50% open after the logs are burning well.  This will heat the hot room and not send the heat up the chimney.  Once you achieve the desired temperature, you can close it almost completely.

Is it approved to UL standards like the Classic Kuuma Legacy?

Not at this time.  We didn't approve to UL standards on the Classic Kuuma Legacy for decades.

Is it brick-lined and baffled?

Yes, it is brick-lined to prevent warpage and, coupled with the baffle, enhances the burning of gases.

How is the steam (löyly) with the Kuuma BluFlame? 

Fantastic steam is a key attribute of a great sauna.  The Lämpömassa behind our design results in amazing steam.  Use only clean, mineral-free water (rain or lake water should work great) on your sauna rocks to make steam.  We strongly recommend that you do NOT use water with a high sodium content (think what our cars in MN look like versus ones that don't see the winter), especially if you don't practice the Bake and Breathe method because salt, heat, steel, moisture, and paint don't play nice and will result in premature rusting.

How important is your chimney draft in successful operation? 

Chimney draft is absolutely essential for the safe, clean, and efficient operation of any wood-burning appliance. Without a sufficient draft, smoke and gases cannot exit the stove properly, leading to poor combustion, creosote buildup, and even potential smoke spillage. A strong, consistent draft ensures that the fire receives the oxygen it needs to burn cleanly, maximizing both performance and safety.

With a gasification sauna stove like the Kuuma BluFlame, maintaining a chimney draft is crucial for achieving optimal efficiency and clean combustion.

Do we supply chimney parts?

No, everything can be sourced locally or online.

For the chimney, a standard 6″ collar is included coming off the stove.  Duravent is a reputable brand that carries all the necessary pieces, including the adapter for ceiling installation, all while meeting the proper codes.

In the chimney, you need a damper for backdraft protection.  It’s best to place it high enough that children can't access it.

You can do a single-walled pipe from the stove up until 18″ below the ceiling.  Then you need to switch to double or triple-walled, Class A pipe through the top.

If possible, go straight up from the stove through the ceiling. If you must make a 90*, use (2) 45*’s and make a radiant bend instead of a hard 90*.

If you use a chimney cap, it needs to be the open kind (click here).  This is the one we use, and it works great!  Famco (Wind Directional Chimney Cap)

Kuuma Chimney Kit & Installation Guide

Does my Kuuma stove come with rocks?

No, but we recommend granite or quartz, often found locally at lakes and streams. Make sure they aren’t cracking or porous. Many retail landscaping businesses often sell them as well.  We recommend a golf ball to a tennis ball in size, with a slight variation.  Please wash with warm water and soap before installation if you pick your own. Sauna Rocks

How much rock do I want on the Kuuma BluFlame?                                      

The choice is yours.  You can have 100lbs – 250lbs on the small and 100lbs – 300lbs on the medium.  More rock can lead to longer heat-up times and can also be a heat sink.  I've found rock recovery to be the most critical factor for my personal sauna style most of the time.  My sweet spot is 125-175lbs (small) and 150-200lbs (medium), which typically takes 60-90 minutes of heat time.  If you go with 200lbs +, expect a longer heat time since it's 650lbs+ of lämpömassa.

Do we recommend a dedicated vent to draft our Kuuma Sauna Stoves?

Yes,  A 4" low-mounted, dedicated outside-air vent located near the stove provides sufficient combustion air for proper drafting of all Kuuma wood-fired sauna stoves when installed with minimal restriction and a direct path to outdoors.

Can you heat water for bathing while it heats the room?

Not at this time.  We are in the process of developing a water tank with the goal of making it retrofittable for any current BluFlame owners.

Can you see the fire?

Yes, it includes a large glass window so you can watch the burn, provide an additional light source, and make your sauna experience even more romantic and enjoyable.

Is the glass window easy to clean?

If ever needed, it's easy to clean by dipping a wet rag into ash (or ammonia works great) located in either the firebox or ashpan and wiping with a microfiber cloth.  If you need to clean your window daily, you are probably smoldering the wood.  There could be an issue with your wood (not seasoned) or draft (too much or too little), resulting in poor combustion.  This should be easy to fix.

The small gap is intentional (video).

What size room will it heat?

Based upon how well the heating room is insulated, the small stove is for up to an 8′ x 8′ x 9′ room, and the medium is for up to 10′ x 10′ x 9′.  We've used both stoves in larger hot rooms than recommended.  Because of their high efficiency, they have been able to heat them, but it will take longer.

Why is my stove door hard to open?

This can happen on occasion when the stove is drafting hard, usually early on in the burn process.  It's best only to open the door or to reload on a coal bed.

How long should it take to heat my sauna?

Many factors (see blog post) come into play when determining how long it will take to heat your sauna.   What kind of wood are you using?  What material is your sauna constructed out of?  Do you have a damper on your stove pipe?  If so, it might need to be adjusted specifically for your local conditions.  Otherwise, you could be shooting all of the hot air up the chimney.

What length of wood works best?

Ideally, 14-15" wood lengths for the small and medium Kuuma BluFlames.  14-15" lengths are ideal, so when the bottom row is gone, and the top rows drop down to replace it, they aren't restricting the bottom of our air draft control even slightly.

Did my stove back puff?

The Kuuma BluFlame is a pressurized firebox designed to function with a natural draft.  Occasionally, this can happen when the stove is drafting hard, and you open the stove door to add or adjust wood, usually early in the burn process.  It's best only to open the door or to reload on a coal bed.  If you're in a rush to reload, open the damper all the way to burn the wood faster.  The other end of the spectrum, having enough draft for the stove, is also essential.  It should be easy to accomplish by following our chimney recommendations.

Recommended Maintenance of a Kuuma Wood Burning Sauna Stove (Annual or as needed)

See (blog post here).

These few simple steps will help you protect, keep it looking nice, and extend the longevity of your KUUMA sauna stove for years or decades to come.

Can you load wood from outside the dressing room?

Not at this time.  It's possible that we could add this option in the future.

**Inside versus Outside Feed Blog**

Do Kuuma wood-fired sauna stoves require a UL-rated or insulated hearth?

Hearth requirement: A non-combustible ember-protective surface only. No UL-rated or insulated hearth is required.