Deep Cleaning and Maintenance Guide for Wood Burning Stoves

For frequent users of wood burning stoves, whether in saunas or hot tubs, long term use inevitably leads to the accumulation of soot and wood tar inside. Without cleaning, this can affect the stove’s heating efficiency, cause flue blockage, and even create safety hazards. To ensure safe, efficient, and long lasting use, we will introduce the structure and materials of wood burning stoves and summarize a comprehensive cleaning and maintenance guide.

Wood Burning Stove Structure

The internal structure of the wood burning stoves is not complicated. It mainly consists of a furnace, flue, chimney inlet, chimney cap, outer shell, and base. Each part supports the heating and smoke exhaust functions of the wood burning stove.

Furnace

The furnace is the most crucial area of the entire wood burning stoves, where firewood is stored for combustion. It is constructed of welded cast iron and has a large internal space.
The furnace chamber has a perforated iron plate that allows the ashes of the burned firewood to fall into the ash collection drawer below, preventing the firewood and ashes from piling up together and hindering combustion.

Flue and Chimney Interface

A chimney inlet is located above the furnace for connecting the chimney pipe. Extending upwards from the center of the stove, you can see the stainless steel chimney and the external heat insulating cover. These components effectively exhaust combustion fumes and provide heat protection to prevent burns. Over time, the stainless steel chimney will gradually turn black due to carbon buildup in the fumes. This is a normal phenomenon and nothing to worry about.

Chimney Cap

The top of the wood burning stove is a disc shaped cover supported by three metal bars. It is made of the same stainless steel as the chimney itself. The suspended top design reduces backflow of flue gas and prevents leaves, animals, and other debris from entering the chimney, thus avoiding blockages or safety hazards.

Shell

The black painted cast iron exterior, combined with the perforated furnace design, allows air to flow freely and create convection, significantly improving the heating speed of the wood burning stoves while also providing robust protection for the internal furnace. The furnace features a glass and stainless steel door with a metal spring handle, making it easy to observe the burning status of the firewood and effectively preventing burns, combining safety and practicality.

Metal Support Feet

The wood burning stove is supported by four metal feet, which not only enhance its overall stability but also ensure that the stove remains level even on uneven ground. The metal material is sturdy and durable, providing solid load bearing and stable support for the entire stove.

Preparations Before Cleaning the Wood Burning Stove

Before cleaning the wood burning stoves, thorough preparation is necessary. Preparing the cleaning tools and ensuring the stove has cooled down beforehand are the first steps in the cleaning process.

Cleaning Tools

Before cleaning the wood burning stoves, you need to prepare cleaning gloves, masks, soft brushes, glass cleaner, soft clothes, stove polish, fire tongs, and chimney cleaning rods.

Cooling Stove Body

Check if there are still burning embers inside the furnace. Use tongs to remove any unburnt or smoldering firewood and let it sit for a while to allow the furnace to cool down. Cleaning before it has cooled down will cause soot to rise, and the high internal temperature can cause burns.

Clean the Furnace

Before diving into regular or deep cleaning steps, it’s important to understand why proper maintenance matters. A well-cleaned wood burning stove not only burns more efficiently but also extends the lifespan of your heater, keeps the air flowing smoothly, and ensures every future sauna session starts with a clean, safe, and satisfying fire.

Cleaning the Internal Ash

First, gather all the ash from the furnace into the ash collection drawer at the bottom. Use a shovel or wooden stick to sweep the ash off, cleaning as much as possible from the edges and corners. If you plan to continue using the wood burning stoves in the near future, a thorough cleaning is unnecessary. A simple cleaning is sufficient. After this simple cleaning, slowly pull out the ash collection drawer and empty the ash into the trash can. Excessive ash residue inside the stove will obstruct airflow, reduce combustion efficiency, and affect future use.

Deep Cleaning

If the wood burning stoves will not be used again for a period of time after its initial use, a deep cleaning of the inside of the furnace is recommended. Use a soft bristled brush to scrub away the accumulated ash inside the furnace, and gently brush away stubborn soot and tar deposits on the bottom and inner walls of the furnace to prevent them from accumulating over time, causing odors and corroding the metal inner walls.

Cleaning the Furnace Glass Door

Use glass cleaner with soft clothes and soft brushes to wipe away deposits on the glass and clean the gaps in the stove glass door. This will allow you to clearly see the burning inside the stove the next time you use it, making it easier to add firewood.

Inspect and Clean the Chimney

Secondly, checking and cleaning the chimney is also very important for using wood burning stoves. The clogged chimney can pose a serious fire hazard.

How to Dismantle a Chimney

While different brands and models of wood burning stoves may vary slightly in details, there are essentially three ways to connect the chimney: slip in, clamp lock, and ring lock. The chimney disassembly steps are generally the same. First, ensure the stove body and chimney are completely cooled. Then, loosen the external retaining ring (if present), firmly grasp the chimney tube with both hands, gently rotate it left and right, and pull it upwards. If the chimney consists of multiple sections, remove them one by one from top to bottom. Throughout the process, avoid rough handling to prevent deformation of the stainless steel chimney, which could affect future installation and sealing.

Chimney Deep Cleaning Steps

Deep cleaning the chimney is a core step in ensuring the safe use of the wood burning stoves.
Before cleaning, lay large garbage bags on the ground to catch falling ash. After erecting the chimney vertically, slowly insert a chimney brush from the top and repeatedly pull it up and down to scrape off the tar and ash adhering to the inner wall. If the tar buildup is particularly severe, it is recommended to use a mild, non toxic oil cleaner to improve cleaning efficiency.
After cleaning, wipe the outer wall of the chimney with a dry cloth and check each section for cracks, deformation, or poor sealing at the joints, replacing any sections as necessary. Keeping the chimney unobstructed is crucial to preventing backflow of flue gas, avoiding fire risks, and ensuring efficient combustion in the wood burning stoves.

Built In and External Wood Burning Stoves

Built in wood burning stoves are popular among sauna users due to their compact structure and clean appearance. They not only reduce the high temperature exposure of components, resulting in more even and stable heat dissipation, but also simplify routine cleaning. Typically, complete disassembly is unnecessary. Simply insert the chimney brush from the top or bottom and repeatedly pull the handle up and down to remove accumulated ash.
External wood burning stoves are mostly used in hot tubs or outdoor portable saunas, with a relatively simple and intuitive smoke exhaust path. Users can clean them without disassembling them, or easily remove the entire chimney for deep cleaning, followed by scrubbing from the inside with a long handled brush. Because it’s an external wood burning stove, there’s no need to worry about soiling the internal environment, making maintenance easier and allowing for more flexible and reliable use in outdoor settings.

Maintenance Tips

To keep your wood burning stoves in top condition, Alphasauna, as the manufacturer, has summarized some very practical tips for use and maintenance.

Pre Use Check

Before each use, it is recommended to test the smoke exhaust by burning a small amount of firewood or paper to ensure it is normal and smooth. If backflow of smoke occurs, stop using the chimney immediately and check for deformation or damage. Replace any damaged chimney pipes if necessary.

Daily Cleaning

After each use, clean and discard the ash inside the furnace to avoid excessive accumulation that could affect airflow and combustion efficiency. Long term neglect of cleaning may also damage the furnace structure.

Regular Deep Cleaning

We recommend a systematic cleaning once a month, checking for chimney blockages and using a long handled brush to clean away tar deposits. For the furnace, gently brush away accumulated ash with a soft bristled brush to maintain a good combustion environment and extend the lifespan of the heating equipment.
A comprehensive maintenance should be performed annually, inspecting the stove body for cracks, paint peeling, etc., and replacing or repainting necessary areas.

Choose Firewood

It is recommended to choose dry firewood with low moisture content that is less likely to produce tar, such as pine, birch, and oak, as these burn more cleanly. Avoid using non firewood fuels such as cardboard and plastic, or damp or chemically treated wood, as these will produce large amounts of harmful fumes and tar, increasing the difficulty of cleaning up.

Pay Attention to the Usage Situation

If the glass door of the furnace turns black too quickly, you need to check if the flue is blocked or if too much firewood is added at once. This may be due to insufficient ventilation. You should reduce the amount of firewood added or fix the flue problem.

FAQS

Question1：Which Is Safer: A Hot Tub with a Built In Wood Burning Stove or an External Wood Burning Stove?

Answer:If safety is your top priority (especially if there are children or elderly people in the household), an external wood burning stove is recommended.
If space is limited and you want to heat up quickly, you can choose a built in wood burning stove. However, please note the following:
1. A stainless steel cover/wooden partition is required.
2. When using, avoid touching the stove body.
3.Regularly stir the water temperature to prevent any localized overheating.

Question2:Which Heats Faster, An Electric Stove or a Wood Burning Stove?

Answer:Wood burning stoves heat up faster because their power is typically 15 18KW, while electric stoves can be selected from 4.5 18KW depending on the size of the sauna or hot tub.

Question3:Can the Temperature of Wood Burning Stoves and Electric Stoves Be Controlled to What Level?

Answer: Electric stoves can reach temperatures as high as 110 degrees Celsius, while wood burning stoves can reach even higher temperatures.