14 best double-circuit heating boilers

Review of the best according to the editorial board. On the selection criteria. This material is subjective and does not constitute advertising and does not serve as a purchase guide. Before buying, you need to consult with a specialist.

Double-circuit boilers have two heat exchangers inside that take heat from the burner for heating and heating hot water. The second circuit can operate autonomously, for example in the summer to supply hot water to taps and showers. This is the most practical heating equipment for apartments, private houses and summer cottages. We propose to consider the rating of the best double-circuit heating boilers, divided into categories. To compile the TOP-14, we studied the characteristics of the goods and customer reviews, which will help to know in advance all the pros and cons of popular models.

Rating of the best double-circuit heating boilers

Nomination a place Name of product price
The best double-circuit wall-mounted heating boilers 1 Vaillant turboTEC pro VUW 242 / 5-3 RUB 55 881
2 BAXI NUVOLA-3 Comfort 240 Fi RUB 83 882
3 Buderus Logamax U072-35K RUB 45 150
4 Bosch Gaz 6000 W WBN 6000-35 C RUB 44,225
5 Ariston CARES X 24 FF NG RUB 29 800
6 Viessmann Vitopend 100-W A1JB010 RUB 42,539
7 Navien DELUXE COAXIAL 24K RUB 26,500
The best double-circuit floor heating boilers 1 BAXI SLIM 2.300 i RUB 115,638
2 Vaillant ecoCOMPACT VSC INT 266 / 4-5 150 RUB 176 300
3 Lemax Premium-30B RUB 34,200
4 Navien GA 23KN 34 570 rub.
The best double-circuit condensing boilers 1 Buderus Logamax plus GB172-30 iK RUB 94,200
2 BAXI Duo-tec Compact 24 RUB 52,158
3 Protherm Lynx condensing 18/25 MKV RUB 61,200

The best double-circuit wall-mounted heating boilers

Wall-mounted boilers are characterized by compact dimensions within the range of 700x300x400 mm. This allows them to be installed in the kitchen, for example, above the table, so that the equipment can be easily controlled and adjusted. Due to its small size and wall placement, the boiler does not take up floor space and becomes an ideal option for apartments or houses with a small kitchen area. Here are the best two-circuit models of this kind.

Vaillant turboTEC pro VUW 242 / 5-3

Rating: 4.9

Vaillant turboTEC pro VUW 242

The first place in the rating is taken by a convection boiler with a capacity of 24 kW. A two-circuit device is suitable for heating a house with an area of ​​up to 250 m². The efficiency is 91%. Customers in reviews love the attractive design of the model with a blue screen and touch-sensitive controls. Decent appearance will serve as a decoration in the room where it will be placed. There is already a circulation pump inside the boiler, so the coolant will regularly move along the heating circuit. The closed combustion chamber increases safety. The double-circuit boiler works with a 60/100 mm coaxial chimney, but it can also be connected to a separate one. Flame modulation allows you to adjust the heating at the desired speed and with a certain frequency.

We added this product to the rating because it works very quietly, which is confirmed by the owners in the reviews. Despite the presence of a pump, the circulation is almost inaudible. The 6 l expansion tank does not emit unnecessary sounds during the thermal movement of materials. Thanks to the closed chamber, the burners operate silently. This is the best choice if the boiler needs to be installed close to the bedroom.

Advantages

  • compact dimensions 440x800x338 mm;
  • the set includes everything you need for connection (gas pipe, two pipes for the circuits, crimp adapter);
  • 3 year warranty;
  • attractive appearance;
  • quiet work.

disadvantages

  • high price;
  • the wall model weighs 40 kg and is difficult to install yourself;
  • expensive spare parts that are scarce on sale;
  • complex menu;
  • an additional inlet filter is required (sensitive to water quality).

BAXI NUVOLA-3 Comfort 240 Fi

Rating: 4.8

BAXI NUVOLA-3 Comfort 240 Fi

In second place in the rating is a stylish two-circuit model from the Italian brand Baxi. The gas boiler works on the convection principle and produces a power of 24.4 kW. The device is equipped with electronic control and operates from both natural and liquefied gas. The primary heat exchanger is made of copper, which protects the structure from corrosion and accelerates heat transfer. The owners in the reviews share that the dual-circuit device is able to regulate the temperature of water and heating itself, focusing on the weather, but this will require an additional purchase of an external temperature sensor. The heat carrier is heated to a temperature of 85 degrees, and the DHW circuit to 60 degrees C.

Our experts put the two-circuit model in the rating because it is a mini-boiler room in one building. The boiler has a 7.5 l expansion tank, a 60 l boiler, which is quite enough for washing two people, the ability to connect a warm floor. The equipment also has a system for quickly heating water in the boiler – 30 degrees are reached in 30 minutes. The best model in terms of productivity – 14 l / min at 25 ° C.

Advantages

  • the chimney does not freeze in winter;
  • works from a low pressure of 5 mbar;
  • Efficiency 93%;
  • removable control panel;
  • automatic ignition and programmer.

disadvantages

  • high price;
  • expensive service;
  • large dimensions 600x950x466 mm;
  • there is no outdoor temperature sensor included;
  • difficult to set up weekly programming.

Buderus Logamax U072-35K

Rating: 4.7

Buderus Logamax U072-35K

The third position in the ranking belongs to the Buderus brand with its two-circuit model Logamax U072-35K. The convection boiler has a closed combustion chamber and a circulation pump. The latter is protected from jamming, for which the impeller turns on every 24 hours, even if the heating is not working. The product is made in a white case with a black control panel and a small display without backlight. An expansion vessel of 10 liters compensates for any increase in the volume of the heating medium. For the equipment to work correctly, a gas pressure of 10 mbar is sufficient. In the second circuit, the temperature is regulated from 35 to 60 degrees. Automatic diagnostics helps to find the cause of the breakdown by displaying an error code on the screen. Buyers in the reviews note the ease of customization – the front panel contains only five buttons. The menu is clear and simple.

We have included a double-circuit boiler in the rating of the best because of its high heat output, which is adjustable from 12 to 35 kW. For the wall model, this is a high figure, which is enough for a spacious house with an area of ​​350 m². The device heats up reliably and can operate from liquefied gas in cylinders.

Advantages

  • there is autodiagnostics;
  • copper heat exchanger;
  • auto ignition and flame modulation;
  • frost protection;
  • gas availability control.

disadvantages

  • high price;
  • weighs 39 kg;
  • condensate accumulates in the differential pressure sensor tube – protection is activated;
  • works worse with a coaxial chimney, but loud without it.

Bosch Gaz 6000 W WBN 6000-35 C

Rating: 4.6

Bosch Gaz 6000 W WBN 6000-35 C

The fourth step in the ranking of the best belongs to the German model GAZ6000W from Bosch. The double-circuit device has dimensions of 485x700x315 mm and weighs 39 kg. It can be operated from liquefied propane-butane with a pressure of 25 mbar or from a gas line with a pressure of 10 mbar. There is a copper heat exchanger inside. The second circuit heats the shower water with a capacity of 14 liters per minute at a temperature of 30 ° C. To cope with a large heating area, the nozzles burn up to 3.9 m³ of gas per hour at a frost of -30 degrees. The built-in pump ensures fast heat transfer to the radiators. The ON indicator shows the state of the boiler. The two-circuit model is equipped with a safety valve and an air vent that removes bubbles from the system.

This product is also included in the rating as one of the most powerful wall-mounted double-circuit boilers. The device has a thermal power of 37.4 kW, which is enough for an area of ​​370 m². Users in the reviews share that he easily copes with heating a house, garage, bathhouse and underfloor heating while simultaneously connecting all circuits.

Advantages

  • quiet work;
  • built-in analog pressure gauge and does not depend on electronics;
  • closed combustion chamber;
  • own pump for circulation of the coolant through the heating system;
  • prevention of freezing.

disadvantages

  • periodically, the board gives an error and you need to restart the boiler;
  • when using hot water, the temperature in heating drops slightly;
  • chimney freezes in winter;
  • high price.

Ariston CARES X 24 FF NG

Rating: 4.5

Ariston CARES X 24 FF NG

The fifth place in the rating is given to the goods from 'Ariston'. The Cares X24 FF NG double-circuit boiler is cheaper than the competitors described above, but it looks just as attractive. The front panel contains a gray insert with touch buttons and a black screen with bright blue numbers. This does not create a 'flashlight' effect in the dark, and is clearly visible during the day, which customers like in the reviews. The power of the convection equipment is 25.8 kW, which is enough for a spacious house with an area of ​​260 m². The boiler is connected to a single-phase network to power the electronic control board, indicators and protection functions. The kit contains everything you need for connection: отопления “gas and heating circuit pipes, ½” DHW pipe. Optionally, you can connect a remote control and configure the boiler operation remotely.

We added a double-circuit boiler to the rating due to the presence of a water filter inside. The built-in cleaner prevents the heat exchanger walls from 'fouling'. This protects the entire heating system, including the pump.

Advantages

  • compact dimensions 400x45x319 mm;
  • designed for 10 years of operation;
  • there is a frost prevention mode in an unheated house;
  • gas supply control;
  • overheat protection.

disadvantages

  • you can hear the burners burning;
  • high gas consumption;
  • often gives a flame separation error.

Viessmann Vitopend 100-W A1JB010

Rating: 4.4

Viessmann Vitopend 100-W A1JB010

The sixth position in the rating belongs to the product from the world brand Viessmann, the household line of which is distinguished by its unpretentiousness. By design, this boiler stands out from the competition by the location of the buttons and the display on the lower edge of the front panel. This minimalist style is well suited for a high-tech or loft kitchen. The power of the double-circuit boiler is 24 kW. The efficiency is 91%. The closed combustion chamber receives air through a coaxial chimney with dimensions 60/100 mm. For smooth operation, there is already a pump for pumping the coolant and an expansion tank for 6 liters inside. Heating operates with a maximum heating of the primary circuit up to 80 degrees. Heating water for showers and sinks in the second circuit reaches 57 ° C.

In our opinion, the product has earned a place in the ranking due to its high build quality. This is a good boiler that can last 10-15 years. He also has a programmer that allows you to set heating parameters for the whole week (cooler – during the day on weekdays, warmer – in the evenings and weekends), which reduces manipulation of the dashboard to a minimum.

Advantages

  • convenient access to parts and assemblies;
  • designed for 10 years;
  • functions of autodiagnostics and protection against blocking of the pump;
  • the ability to connect a remote control;
  • compact dimensions 400х725х430 mm.

disadvantages

  • weighs 32 kg;
  • if you open two taps at the same time, then cold water flows for a long time;
  • makes a lot of noise during work;
  • error F6 periodically pops up.

Rating: 4.3

Navien DELUXE COAXIAL 24K

The seventh position in the ranking among wall-mounted boilers is taken by a product from France. The double-circuit heating equipment has a power of 24 kW and an efficiency of 90.5%. The front panel contains only the brand name and an analog pressure gauge. There is a pump and an expansion tank inside. The heat exchanger is cast from stainless steel and does not corrode. The boiler can operate on liquefied gas, consuming a maximum of 2.15 kg / h, or from the mains with a consumption of 2.58 m³ / h. When water is heated in a shower (with a temperature of 25 ° C), the productivity will be 13.8 l / min. Features include flame modulation, thermostat, auto ignition and thermometer.

Buyers in the reviews like the ability to accurately adjust the temperature in the DHW circuit, regardless of the indicators in the heating system. We have included the product in the rating, since the boiler quickly heats up the coolant. After switching on, after a couple of hours, the apartment will be warm. Another two-circuit unit has an external split panel with a screen and buttons (included in the standard package, and not purchased separately, like from competitors). Thanks to this, the boiler will be in one room, and its operation can be adjusted from another.

Advantages

  • closed combustion chamber;
  • attractive price;
  • stainless steel heat exchanger;
  • rapid heating of the heating.

disadvantages

  • the external control panel quickly breaks down (the buttons stop responding);
  • weak circulation pump;
  • there is no screen and buttons on the boiler itself;
  • control of water pressure must be carried out manually.

The best double-circuit floor heating boilers

Double-circuit types of boilers usually take up more space, but have increased power. This allows them to be used for heating large houses, cottages and commercial premises. The devices are installed, as a rule, in the boiler room, where the gas main, heating and hot water supply lines are supplied.

BAXI SLIM 2.300 i

Rating: 4.9

BAXI SLIM 2.300 i

In the first place in the rating in the category of floor standing boilers are products from the Italian brand Baxi. The gas convection double-circuit model has a capacity of 14 to 29.7 kW, which covers the heating needs of a house with an area of ​​300 m². The boiler has an open combustion chamber protected by a small panel. It contains control keys and a display. Removal of the remote control is optionally provided. The efficiency of heating equipment is 90%. The coil inside is poured from cast iron and does not cool down for a long time even in the absence of heating. The owners in the reviews like the presence of a 50 liter boiler, which allows you to have hot water in stock and use it even if the electricity or gas is cut off the next day.

According to our experts, the floor-standing double-circuit boiler should have been added to the rating due to its compact dimensions 65x85x60 cm.For equipment in this category, such dimensions are rare and the model is called Slim for a reason. But despite the small dimensions, the productivity in the hot water system is 17 l / min, if the water temperature is 30 degrees.

Advantages

  • there is a 50 liter boiler;
  • a primary heat exchanger made of cast iron keeps heat for a long time and saves gas;
  • works from a cylinder and a line;
  • supports the connection of a warm floor;
  • there is a display and the possibility of external introduction of settings from another room.

disadvantages

  • high price;
  • open combustion chamber;
  • weight 192 kg;
  • a gas pressure of at least 20 mbar is required;
  • under the chimney with a diameter of 14 cm, you need to punch a large hole.

Vaillant ecoCOMPACT VSC INT 266 / 4-5 150

Rating: 4.8

Vaillant ecoCOMPACT VSC INT 266 / 4-5 150

The second position of the rating is occupied by EcoCompact, although it is difficult to call it compact. The double-circuit floor-standing boiler has a height of 164 cm and definitely needs to be placed in a boiler room. But such dimensions are justified by the presence of a 150-liter boiler, which is enough for a family of 5-6 people, which customers approve of. The power of the unit is 25 kW. The circulating pump provides fast circulation through the system. Autodiagnostics monitors the main components. When the coolant boils, overheating protection will work. The pressure gauge reports the pressure in the system – the DHW circuit will withstand up to 10 bar. External control is optional. The maximum gas consumption is 3.24 m³ / h.

We have added a double-circuit floor-standing boiler to the rating due to an efficiency of 106.5%. This is achieved by two stainless steel coils, which perfectly absorb heat and quickly release it to water. The product also features an ultra-modern design with hidden buttons and a display.

Advantages

  • boiler for 150 l;
  • expansion tank 12 l;
  • regulation of the coolant temperature from 30 to 80 degrees;
  • hot water productivity 12.3 l / min;
  • frost prevention mode.

disadvantages

  • the cost is very high;
  • weight 126 kg;
  • huge dimensions 60x164x69.3 cm.

Lemax Premium-30B

Rating: 4.7

Lemax Premium-30B

In the third place in the rating is the boiler from the Lemax brand. The product is manufactured in Russia and is maximally adapted to real operating conditions. The two-circuit floor-standing model has a power of 30 kW and an efficiency of 90%. The appearance of the boiler is very modest, with a beveled top. The settings are adjusted mechanically by acting on the gas and water supply valves. But the equipment has flame control and overheating protection, which really works. The thermometer is placed on the upper part of the case to make it easier to monitor its readings. The open combustion chamber is located behind the front panel cover. The dimensions of the boiler are 56x96x47 cm.

All owners in reviews praise him for the good warming up of the house even in frosts of -20 degrees. This is possible due to bringing the circulating fluid up to 90 ° C, which not all dual-circuit competitors are capable of. The boiler is also non-volatile – if the light is turned off in the private sector or in the country, the heating will not be affected.

Advantages

  • more affordable price;
  • suitable for a heating area of ​​300 m²;
  • the cost of spare parts is cheaper than that of competitors;
  • economical gas consumption;
  • heats the coolant up to 90 degrees.

disadvantages

  • rustic design;
  • open combustion chamber;
  • noisy work;
  • steel coil;
  • no pump – you need to buy it separately.

Rating: 4.6

Navien GA 23KN

The fourth step in the rating in the category of floor standing boilers with two circuits is given to the French apparatus with a power of 23 kW and an efficiency of 91.5%. This is a modern model with electronic control and power supply from a single-phase 220 V. It has a closed chamber where gas is safely burned. When the flame goes out, the valve shuts off the blue fuel supply. Gas consumption is no more than 1.96 kg / h. The double-circuit heating system has dimensions of 38x86x63 cm and weighs 74 kg. A built-in thermometer and pressure gauge provide the necessary information. If you need to leave for a few days, a freeze prevention mode is provided.

We've ranked the product in the top ranking because the double-circuit floor model has an attractive design. Control buttons and key indicators are hidden under the glass, but are easily accessible. Ornate patterns on the door make the exterior look interesting. Both circuits are also capable of fully functioning with an incoming gas pressure of 10 mbar, which is not within the power of all competitors from the rating. The French manufacturer provides a room thermostat for it, which allows you to set the settings without visiting the boiler room, which consumers like in reviews.

Advantages

  • affordable price;
  • closed combustion chamber;
  • there is a weekly programmer;
  • complete with remote control with display.

disadvantages

  • without circulation pump;
  • weighs 74 kg;
  • no air removal system;
  • volatile.

The best double-circuit condensing boilers

Condensing boilers use the energy released during condensation to heat the return. A short time after starting, warmer water is supplied to the burner, which allows less gas to be spent on heating it and makes the temperature in the heating circuit even. This helps to save blue fuel, but the price of double-circuit condensing boilers is quite high.

Buderus Logamax plus GB172-30 iK

Rating: 4.9

Buderus Logamax plus GB172-30 iK

The first position in the rating belongs to a two-circuit condensing model with a maximum power of 30 kW. This is a wall-mounted boiler with a 12 l expansion tank and an electronic control circuit powered by a single-phase network. The equipment of the device includes: overheating protection, gas control, display, auto ignition, thermometer, indicator of the on state, pressure gauge. Buyers in the reviews share that the power range from 4 to 30 kW is practical for subsequent plans to expand the house. While the area is small, you can save and reduce the consumption to a minimum, keeping heat. When additional rooms or a garage appear, the boiler can easily cope with an extended heating circuit.

Our experts liked the double-circuit boiler for its 109% efficiency, which surpasses other products in the rating. This efficiency is achieved by an aluminum main heat exchanger enclosed in a circular housing with a burner inside. The product is also notable for its casing, which has a titanium glass front panel, which can be white or black.

Advantages

  • low emission of СО²;
  • stainless steel tank with copper secondary heat exchanger;
  • available in black and white;
  • Beautiful design;
  • wide power range.

disadvantages

  • high price;
  • volatile;
  • no boiler.

BAXI Duo-tec Compact 24

Rating: 4.8

BAXI Duo-tec Compact 24

The second place in the rating was taken by the Italian model with a power range of 3-20 kW and an efficiency of 105.8%. It is a double-circuit condensing boiler with a stainless steel coil, fueled by natural gas and LPG. It has a 7 liter expansion tank, an on indicator, a bright display, and a circulation pump. The device weighs 34 kg and requires the connection of a coaxial chimney with a diameter of 10 cm. The communications inside withstand a pressure of 3 bar in the heating circuit and 8 bar in the hot water supply. If the indicator increases, then the safety valve will work so that nothing inside will break.

Our experts have rated the product as one of the best because it is able to operate with a low inlet gas pressure of 5 mbar. This is relevant for remote villages with a weak gas pipeline or connections from a cylinder. The boiler is also equipped with a protection against blocking the impeller, which starts rotation for a short time once a day. As always, Baxi integrates a water filter into their best boilers to extend the life of the pipes and pump.

Advantages

  • stainless spiral inside;
  • compact dimensions 40x70x30 cm;
  • will last 10 years or more;
  • there is a filtration of the supplied water.

disadvantages

  • high price;
  • the burner almost does not turn off at a coolant temperature of 40 degrees;
  • high consumption – 10 m³ of gas with an area of ​​90 m² in warm winter.

Protherm Lynx condensing 18/25 MKV

Rating: 4.7

Protherm Lynx condensing 18/25 MKV

Our rating ends with the Lynx model assembled in Slovakia. This is a double-circuit condensing boiler with a vertical burner. The secondary heating compartment is made of stainless steel. The equipment is produced with two indicators of maximum power for 18 and 25 kW, which is chosen depending on the area of ​​the house. Buyers in reviews like the clear designation of nozzles with blue and yellow plugs (heating and hot water circuits). The drain and safety valve connection are marked in red. It is impossible to get confused with self-assembly. The boiler efficiency is 104%.

The product was added to the rating due to increased safety – all buttons are touch-sensitive and reliably protect the user even when pressed with wet hands. The primary heat exchanger is made of an aluminum-silicon alloy for increased efficiency. With the front bezel removed, it is easy to reach the loop switch servo for easy seasonal readjustment.

Advantages

  • the house heats up quickly;
  • quiet work;
  • gas savings of 10% compared to a conventional boiler;
  • the display does not dazzle in the dark;
  • touch buttons.

disadvantages

  • high price;
  • operates only on natural gas (does not support work with a cylinder);
  • a filter or descaling is required;
  • looks very simple.


Attention! This rating is subjective and does not constitute an advertisement and does not serve as a purchase guide. Before buying, you need to consult with a specialist.

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