Bath boiler: popular varieties and how to choose them

Despite the fact that on our website you will find many articles devoted to cast iron stoves in the context of Russian baths and saunas, as well as various types of fuel used, not to mention the rating and review of the best models on the Russian market, users still have many questions to which we haven't answered yet. This article is an attempt to correct this state of affairs. We will start with the most stable ideas, talk about stoves entirely and only partially made of cast iron, and also about much more.

The truth about cast iron sauna stoves

Despite the conspiratorial nature of the title, we will talk about common fears before buying a stove - cast iron sauna stoves are not cheap, no one wants to make a mistake. So, the first concern:

Cast iron sauna stoves are fragile

Well, in general, this is a completely justified fear, given that these are precisely the properties of the metal itself, which contains large amounts of carbon . However, the following point should be taken into account:

Attention! Cast irons are very dependent on compliance with technological rules . When properly heated and tempered, graphite does not form plate-like crystals, but balls, which improves the characteristics of such cast iron. But this is typical for certain brands, and not for ordinary gray cast iron (GC).

Magnum seemed to boast that the graphite in their furnace metal was spherical.

In general, a cast iron sauna stove is good because it lasts a long time : 20 years is the expected service life of such a unit.

IMPORTANT! However, the owner needs to remember that it is better not to subject his stove to mechanical shocks and sudden temperature changes.

There are crash tests on the Internet in which water is poured onto a hot stove. In principle, this indicates good quality of the metal , but it’s not for nothing that manufacturers protect the cast-iron bottom of the heater from the ingress of supplied water with a steel insert - this is done on purpose so that the cast iron does not burst. Another option is a closed heater made entirely of steel.

Advice! You shouldn’t give your stove a crash test every time: use hot water to top it up (this is better for stones too), and if there is no steel insert from the manufacturer, install it yourself. This is a steel leaf slightly bent in the middle, which is placed on the bottom of the heater.

Useful video

Speaking of crash tests. Look at one of them. Volunteers were found to water only the purchased stove:

Second no less important question:

Does a cast iron sauna stove need a lining?

To answer this, you need to understand why metal furnace linings are needed at all. Of course, not only for beauty. The main purpose is to increase the time a metal stove retains heat obtained from fuel combustion, as well as to soften the harshness of infrared radiation .

By the way! If we talk about the hardness of IR radiation, then cast iron, due to its thickness and composition, differs from a steel stove in the direction of greater softness of radiation, even without a casing. However, even in this case it cannot be compared with the heat from a stone or brick lining.

The brick lining of a cast iron sauna stove makes it similar in sauna properties to a real brick stove. And not only in advantages, but also in disadvantages.

Everyone knows about the advantages of brick stoves - this is an excellent option for lovers of Russian baths, but to achieve its conditions you need to spend a lot of time. A cast iron stove in a brick casing will also heat the steam room longer than without a casing . But it’s either time or quality. Other recommendations on choosing stoves for a steam room are collected in a separate article.

If time is precious and any quality is good, then you don’t have to bother with the casing. For sauna lovers, stoves with grids for stones are good. The steam from them is heavy if you don’t use a steam gun, but if you don’t pour a lot of water, then it’s quite suitable, albeit a dry-air bath.

Interesting! Do not forget that casting cast iron is not an easy task, so many manufacturers limit themselves to putting only a cast iron firebox in their products, sometimes purchased from another company.

Useful video

Criticism of cast iron stoves by representative Konstantin Bely. We think that criticism is also useful, because the facts are the same, you just can look at them from different points of view.

All-cast iron stoves and stoves with only cast iron fireboxes

What's the difference between the two? Steel ones will give off heat faster and cool faster . If you usually have little time and want to quickly start bathing procedures, then a steel firebox with a cast iron firebox will last a long time and heat up quickly.

To regulate convection, soften IR radiation, and retain heat, you can always cover a steel stove with brick or stone (necessarily with vents).

Another differentiating factor is price and weight. A solid one weighs more and costs more.

By the way, you may find this article about all the types of cast iron wood stoves useful.

Sauna stoves made of cast iron

There are few manufacturers of all-cast iron stoves on the market. First of all, companies such as PetrozavodskMash (for example, Karelia-5 classic), Hephaestus (for example, Hephaestus PB-04 M 3K), Magnum, Inzhkomtsentr VVD (some models) come to mind. Svarozhich."

As an example, consider the following model:

Cast iron stove for Russian steam bath

reports that “Russian Steam” is an improved “Kalita TM”. The model is based on the ChT-1 developed by Magnum. The door and tunnel are also made of cast iron. Apparently, the only steel part was a box for stones, that is, a closed heater of a cast-iron stove , but the steel is stainless, so everything is fine: you can pour water without fear - the box will not rust or burst from temperature changes.

Cast iron stove for the Russian steam bath (Inzhkom) photo from the site www.vvd.su.

Let us clarify that “Kalita” “Inzhkom” is, at its core, the same furnace, which Magnum greatly improved, and it sold this basis to “Inzhkomcenter” and produced its own furnaces. Therefore, when it comes to the Kalita sauna stove with a cast iron firebox, it is worth deciding exactly whose products you want to purchase. “Kalit” has many modifications, almost all are expensive, lined with stone.

Bath stove "Kalita" with a cast iron firebox.

Useful video

For those interested, watch the process of assembling the Kalita stove. Filmed right at the factory, along the way it tells about the features of these particular furnaces:

For comparison, here is a video of product assembly:

Stoves with cast iron firebox for baths

On sale you can find a separately sold cast iron firebox for a sauna stove - for example, ChT-1 produced. In this case, it is intended for self-lining with brick or stone.

Useful video

A video comparing the Kalita and ChT-1 cast iron fireboxes:

And if you look at the people's favorite - the Vesuvius Legend stove, it turns out that it is practically only a cast-iron firebox, placed in a “playpen” of rods and strips of metal, where stones are then placed, forming a ventilated casing around the firebox. And there are a great many such ovens. They are fashionable, people love them, and there is less work for the manufacturer.

"Vesuvius Legend" with grid

But this is only one type of stove. Another option would be a steel casing that forms the walls around the firebox; inside this casing there is also a heater - open or closed, or both side by side. Let's look at another popular model:

Sauna stove “Sudarushka M” with cast iron firebox

A typical example of a stove in a steel casing. Only the firebox is made of cast iron, the rest is made of steel. The casing has convection slots , the lower of which are designed to take in fresh air to maintain combustion, and the upper side ones are designed to remove heated air. This design would be optimal only if there was a hot air outlet regulator. In its absence, convection will be considered unregulated.

Sauna stove “Sudarushka M” with a cast iron firebox.

Note that there is a reason to buy stoves with a cast-iron firebox for a bath, because their main advantage is the durability of the part of the stove that is most exposed to thermal loads. Everything else can be made of steel, but for a heater, steel is completely optimal because it transfers heat to the stones faster and is not afraid of water supply.

Cast iron stoves for Russian baths

The question is often asked: is it possible to use a stove with a stone mesh to obtain light steam suitable for a Russian bath? If you pour water on top of the stones, you will get steam, like from a kitchen kettle - completely unsuitable for bathing procedures, because when open, the stones are not able to heat up to the required temperature and create fine, superheated steam.

But there is a trick : if use a steam gun to reach the hottest inner stones in the grid, then the chances of getting the right steam increase dramatically.

However, why make a lottery out of pleasure? It is enough to purchase a stove from the very beginning, which will have a closed heater and adjustable convection, and also a good-quality stone or brick lining. These are the main components of choice for those who are looking for the right cast iron stoves for a Russian bath.

However, to familiarize yourself with the nuances of choice, we recommend that you read our following articles:

Choosing the best stoves for a Russian bath: models with a closed heater and rating the best stoves

Features of stoves for Russian baths

Cast iron stoves for baths, Russian and non-Russian: what is on the market

There are not many cast iron stoves on the Russian market, and there are none made entirely of cast iron. The Finns produce stoves, in particular Aito, which is the prototype of the petro. Aito stoves are manufactured by Narvi Oy. The company's product range includes a line of AK stoves, for example the AK-57 stove. But in the designs of foreign stoves made of cast iron there are only grates, doors and (sometimes) lids. Everything else is simpler and easier to make from steel.

But the domestic manufacturer, knowing the love of Russians for cast iron stoves, fully satisfies the needs of the market. We recommend that you read our review, in which we talk in detail about companies whose units are available to customers today. So we conclude : the only cast iron stoves for baths are Russian.

Rating of the TOP 12 best stoves for saunas with a tank in 2021

Gas cast iron stoves for baths

Not everyone wants or has the opportunity to heat the stove with wood. Therefore, a reasonable question arises: is it possible to purchase a gas cast-iron stove for a bath?

Unfortunately, we found only options that would require converting a wood-burning cast-iron stove into a gas stove. There is no point in doing this type of re-equipment on your own. A gas burner must be installed by a professional and the burner must be certified and inspected by your gas inspector.

In general, gas stoves require permission for installation, the reason for which is their special fire hazard - if you can expect just a fire from a wood stove, then the gas also explodes . That is why we advise you to take into account the legislation and equip stoves with gas burners in accordance with all standards. We have an article in which we talk about all the nuances of installing a gas stove in a sauna.

Briefly about the main thing

Many owners of baths and saunas consider it optimal to use a boiler, that is, a stove supplemented with a water tank. This combination is practical and functional; it provides not only hot water supply for any bath processes, but also helps to heat the premises.

There are several ways to position the tank, based on whether it will be built-in or external. To a large extent, the choice of boiler model is influenced by whether gas, electricity or wood will be used as fuel. The volume of the tank is selected depending on the number of users.

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Water heating

For areas where there is no hot water supply, stoves that have their own means for heating water are relevant. Regardless of what material the stove is made of, it will be either heat exchangers or water heating tanks . In both cases, the source of heat is the fuel on which the unit operates.

On a note! There is a difference in where the heat is taken from - from the stove body or from the chimney. In the first case, you reduce the efficiency of the furnace, in the second, you increase it. In addition, water has a very high heat capacity, which means a large heat consumption to heat it.

Cast iron stoves with heat exchanger for baths

A heat exchanger consists of pipes or a register of pipes, or other structure through which water continuously flows (under the influence of convection and gravity or from artificially created pressure). Being in direct contact with the heat source, the exchanger heats up new portions of water. It can be placed inside or outside the stove body, or it can be a coil that wraps around the chimney.

Cast iron stove with heat exchanger on a pipe.

When purchasing a stove, you should ask whether the manufacturer has ready-made heat exchangers suitable for the model you are purchasing. For example, “Sudarushka M” can be equipped with cast iron heat exchangers if the owner does not want to purchase a tank, which is also optionally supplied with the stove.

Cast iron stove with sauna tank

There are companies that are more concerned with consumer convenience. Thus, at PetrozavodskMash, almost all cast iron products can be equipped with a tank of the required volume at the consumer’s request.

Cast iron stove with sauna tank.

In any case, the manufacturer's website will usually indicate whether they have tanks in stock, whether they fit your model, and other information. True, the tanks may end up in the “accessories” section.

By the way! Tanks come in two varieties: some are somehow hung on a stove or chimney, while others are hung in an adjacent room, communicating with the stove through pipes. In the latter case, a heat exchanger will be needed to heat the water.

You will find more detailed information in the articles: stoves with a tank and with a heat exchanger for wood stoves.

Design options for sauna boilers

The design differences lie mainly in the method of placing the tank and the volume of heated water. The classification covers four installation methods; they all have their own merits and are equally widespread throughout Russia.

Internal tank

The design, in which the water heating tank is located inside the furnace body, is interesting for the following features:

• There is no access to the tank from the outside; it is not visually visible. In most cases, the solution is typical for factory models.
• The internal location ensures maximum water heating speed when compared with other varieties. The container is in direct contact with the combustion chamber; Additionally, the housing prevents heat from leaking out.
• As a rule, such models have a small (25-30 l) volume. They are ergonomic, efficient and keep water warm for a long time.

Model with a compact internal tank Source dekoriko.ru

On the chimney, "samovar"

The water reservoir is located on the chimney, in close proximity to the stove (above it). The samovar tank is a practical solution for hot water supply with the following specifics:

• Heating occurs due to exhaust furnace gases, which significantly increases the overall efficiency of the device. The water remains hot both during combustion and for some time after its completion.
• The solution is considered environmentally friendly and economical if you need to organize hot water supply for a periodically used room.
• The water heats up more slowly than in a design with an internal tank, but the heating speed is sufficient for comfortable use. Productivity depends on the power of the stove and the volume of the tank.
• Heating occurs due to the fact that thermal energy comes not only from the walls of the chimney, but also from the metal body.
• The efficiency of the device can be increased: the closer the tank is located to the furnace (the source of hot furnace gases), the faster the water temperature rises.

Medium volume samovar tank Source prom.st

• The design is reliable, easy to install and maintain. The tank is made of stainless steel and has a rectangular or round shape (at the base).

Remote with heat exchanger

The steel tank is located outside the sauna stove, but is connected to it by a heat exchanger built into the firebox. The system can be described as follows:

• The flame in the firebox first heats the coolant in the heat exchanger (a water circuit built into the firebox), and only then heats the water in the tank.
• There are no restrictions on tank volume in the design. The heat exchanger coil is built directly into the firebox.
• The presence of an intermediate link is the reason for the rather slow rate of increase in water temperature (the slowest of all options).
• High-quality heat-resistant steel is used to manufacture the remote tank. The volume is selected based on the size of the room, usually 35-80 liters. Containers of increased volume (60-80 l) can be angular.
• In order for the water circuit to work with maximum efficiency, the tank is not moved more than 2.5 m from the stove.

Design with a remote tank Source aviarydecor.com

• Despite the slow heating, the remote design is popular. The fact is that if you install it in the washing compartment, you can additionally heat the room.
• The full heating time is affected by the volume of the container and the external temperature. With a volume of 80 liters, heating will take approximately 2.5-3 hours.

See also: Catalog of companies that specialize in engineering systems (heating, water supply, sewerage and others) and related work

Mounted (a type of remote)

A mounted boiler in a bathhouse has the following advantages:

• The metal container is attached to the furnace body, on the side or back, rigidly or using special connectors. Close proximity is the main feature of the design.
• Contact with the hot furnace body (steel, cast iron or brick) ensures a rapid increase in the temperature of the coolant.
• The design is simple in design and installation. It is manufactured as a separate component, so you can refuse to use it if you wish.
• Disadvantage of a metal tank: it is located near people, which increases the likelihood of careless touching and burns.

Wood-burning stove with a hanging tank Source oteplicax.ru

Cast iron boiler for a bath

Boilers should be considered a separate topic related to autonomous heating and hot water supply at home, but due to the fact that some owners install separate boilers in the bathhouse, not wanting to take heat away from the bathhouse stove, we will also touch on this issue.

So, a cast iron boiler for a bath is not a cheap purchase, so I would like it to be cost-effective. It can be the main or secondary source of heat, and it is important what area it will heat .

If, in addition to heating, the boiler is used to heat water, then the best option would be a double-circuit boiler .

Pay attention to the type of fuel - there are boilers that run on coal, wood, and both types of fuel. Focus on the view that is more accessible to you. In this case, it is worth clarifying which of the two will be the main one for your model.

In a wood-burning boiler, the burning time of the fill depends on the volume of the firebox, so models with a larger volume are preferable.

There are boilers whose operation depends on electricity and independent ones . The latter will come in handy in areas where the power often goes out.

+++ This is the truth about cast iron stoves for baths. We hope that the information will be useful to you in practice.

Making a wood boiler

If you know how to use a welding machine, an angle grinder and have spatial imagination, a homemade boiler for a bathhouse can be a budget alternative to purchased models. Self-assembly does not involve complex techniques and does not require expensive materials.

Diagram of a boiler with a water circuit Source sitysun.ru