Considering all of your options, selecting the best heating system for your house can be difficult. Two-circuit boilers and single-circuit boilers with indirect heating are two common options. To make an informed choice, one must be aware of the distinctions between each option as each has advantages and disadvantages of its own.
In a closed-loop system, an indirect heating boiler combined with a single-circuit boiler heats water. Warmth is subsequently distributed throughout the house via the use of radiators or underfloor heating systems that utilize this heated water. The water used in the central heating system is heated by an independent component called an indirect heating boiler. It accomplishes this by sending heat to water in a different tank from a main heat source, such as an oil- or gas-fired boiler.
Conversely, a two-circuit boiler, sometimes referred to as a combi boiler, combines in one unit the functions of heating the house and hot water for showers and faucets. When needed, this kind of boiler heats water straight from the main supply, doing away with the need for an additional hot water tank. Due to their small size and ability to save space, two-circuit boilers are a desirable choice for smaller residences or properties with restricted area.
Hot water availability is a crucial factor to take into account when deciding between a two-circuit boiler and a single-circuit boiler with indirect heating. Hot water is constantly available for bathing, dishwashing, and other household chores thanks to two-circuit boilers, which provide hot water on demand. The availability of hot water during periods of high demand, however, may be restricted by the need for a separate hot water tank in single-circuit boilers with indirect heating boilers.
Costs associated with installation and upkeep should also be taken into account. Since two-circuit boilers don’t need complicated pipework or a separate hot water tank, they are frequently easier to install. When compared to single-circuit boilers with indirect heating boilers, they might initially cost more to buy. Weighing the benefits and drawbacks of each option should also include ongoing maintenance costs.
| Single-circuit boiler | Two-circuit boiler |
| Only provides hot water for heating | Provides hot water for heating and taps separately |
Depending on the heating and hot water requirements of your home, you can choose between a two-circuit boiler and a single-circuit boiler with indirect heating. The only purpose of a single-circuit boiler is to heat water for underfloor heating or radiators. It’s easier and frequently less expensive, but hot taps require a separate water heater. A two-circuit boiler, on the other hand, manages hot water and heating simultaneously, providing convenience but possibly at a higher initial cost. When selecting the best option for your home, take into account factors like space, budget, and the amount of hot water your household uses.
What is a single-circuit boiler
The coolant that is used to heat the heating system is heated by single-circuit gas boilers. Water for a hot water supply is not prepared by a single-circuit boiler. Floor standing boilers are used in locations where the heated area can reach three hundred square meters or more. The power of these heating devices is far greater than that of wall-mounted ones.
Wall-mounted single-circuit heaters can heat an area up to three hundred square meters and are most frequently found in apartments in multi-story buildings. These boilers weigh slightly more than forty pounds and are significantly smaller than floor-standing boilers. A single-circuit boiler mounted on the wall blends in with the interior design. These wall-mounted gadgets are also more useful than their floor-standing equivalents. The most sophisticated wall-mounted single-circuit boiler models have a maximum capacity of 35 kW.
A single-circuit gas boiler is not designed with any intricate parts or mechanisms. This boiler is made up of:
- burners;
- heat exchanger;
- control unit;
- water pump;
- turbine motor (if the boiler with a closed combustion chamber);
- pressure gauge;
- sensors;
- shut-off valves.
One possible accessory for wall-mounted single-circuit boilers is an expansion tank, which is housed beneath the boiler shell. Additionally, the floor heating device, which has a small capacity, may include an expansion tank.
What is a two-circuit boiler
This heating apparatus is designed to prepare hot water in addition to heating the coolant. Compared to its single-circuit counterpart, a two-circuit boiler has a more complicated device. The most intricate gadget has a three-way valve-equipped two-circuit heating device.
There are heating devices with two circuits that have two heat exchangers each. Water in the heating system is heated by one heat exchanger, and water for the water supply is heated by another. The most sensible design uses bithermal heat exchanger-equipped two-circuit heating devices. A heat exchanger like that is dual-purpose. There is another heat exchanger inside the bithermal heat exchanger that is used to heat water for household uses. However, more widely used models are thought to be boilers with independent heat exchangers.
Gas boilers with two circuits are beneficial as they address every issue related to heating a space and preparing hot water. These heating units are very small and blend in naturally with any decor. The two-circuit heating device’s design is similar to that of its corresponding single-circuit device, which is further enhanced:
- A second heat exchanger (if the boiler design provides for it);
- 3-way valve (if the heat exchanger is not bi-thermal);
- inlet and outlet for the DHW pipeline.
Pros and cons of a two-circuit boiler
The device that heats two circuits has numerous benefits. The primary benefit of this apparatus is its boiler, which allows you to heat the room and use hot water simultaneously. You can avoid any additional expenses related to boiler purchases by using a two-circuit boiler. The indisputable benefits and external appeal of two-circuit heating devices should also be credited. Not just in the boiler room, but in any other room, these boilers have an attractive appearance.
The high efficiency of contemporary two-circuit heating equipment enables you to drastically cut utility expenses. With two-circuit boilers, you can precisely control both the water’s temperature in the DHW pipeline and the room’s temperature.
There are a few drawbacks to these heating devices, which include the following:
- disconnection of heating at the moment of taking hot water;
- relatively low productivity in hot water preparation.
What is an indirect heating boiler
Indirect heating boilers are becoming increasingly popular today. You can use the heat from the gas boiler more effectively thanks to this practical gadget. When the heating system is turned on during the winter, the indirect heating boiler draws energy from it. During the summer, when the boiler isn’t used for heating, it draws energy from electric heating elements or, if the settings permit, switches to the summer mode.
Water in the indirect boiler is heated as a kind of byproduct rather than directly. A sizable coil that circulates the heating system’s coolant is located inside these boilers. Thus, the heat exchanger heats the water in the boiler, and the gas boiler heats the water in the indirect coil coil, which is pumped throughout the heating system. It is acknowledged that this type of water heating for the DHW mains is the most advantageous financially.
This boiler’s exterior is primarily composed of steel sheet, while the interior is composed of stainless steel. There is a unique material that has no heat conductivity between the exterior and interior of the indirect heating boiler. Such a boiler’s construction is extremely similar to that of a thermos.
The indirect boiler is typically situated close to the heating boiler. First, the boiler must be passed through with the heated coolant. Such a boiler can be connected to multiple hot water extraction points simultaneously, and the water inside will always be hot. The indirect heating boiler heats the hot water without interfering with the heating system’s functionality.
Such boilers are typically fitted with an extremely effective heat exchanger composed of special steel. Brass heat exchangers are a feature of more expensive indirect heating boilers. Because of the long spiral shape of the boiler’s heat exchanger, water can be heated to the desired temperature in the heating system very quickly.
Pros and cons of a single-circuit boiler and BCN
A single-circuit heating device is frequently used in tandem with a boiler that generates hot water through indirect heating. There are benefits and drawbacks to this tandem. The primary benefit of a boiler of this kind is that it almost never needs maintenance or costs money over the course of its lifetime. This is crucial for areas with voltage dips because the indirect boiler prevents excessive load from being placed on the power grid.
Utilizing an indirect boiler in conjunction with a single-circuit gas boiler is incredibly practical. Since it doesn’t need to drain a lot of water before the hot water starts to flow, this type of boiler uses water in an economical manner. This type of boiler quickly heats water and can be connected to multiple faucets, each of which can be placed in a different area of the home or apartment.
An indirect heating boiler’s heat exchanger runs in a way that completely prevents scale formation. Additionally, the design keeps dangerous microorganisms from growing inside the apparatus. An indirect heating boiler can run without maintenance for more than ten years and doesn’t need to be cleaned on a regular basis.
The indirect heating boiler’s heat exchanger is specially shielded from corrosion. These boiler components are effectively shielded from stray currents in the water mains by this protection.
There are a few minor drawbacks with indirect heating boilers, which include:
- higher cost than their electric counterparts;
- indirect boilers are larger in size than conventional boilers;
Use of a single-circuit boiler and a conventional boiler
Conventional boilers are also utilized with single-circuit gas boilers in addition to indirect heating boilers. While slightly less expensive than indirect heating boilers, conventional electric boilers are still far less effective than them in many aspects. The heating time of a traditional electric boiler is significantly longer, and it needs to be maintained on a regular basis.
Once a year, the electric boiler should be cleaned of limescale, and the anode, which protects the electric heater, should be changed on a regular basis. An independent electric line needs to be installed for the electric boiler, which also requires a dependable power source. Additionally, the electrical grid is generally heavily burdened by this water heater. As a result, it is preferable to use an electric boiler in buildings with safety margins in the electrical wiring.
For homeowners looking for effective heating solutions, selecting between a two-circuit boiler and a single-circuit boiler with an indirect heating boiler can be crucial. The choice ultimately boils down to personal taste and particular household requirements, as each option has pros and cons of its own.
A single-circuit boiler with an indirect heating boiler might be the best option for people who value economy and simplicity. The basic idea behind this setup is that water is heated by the boiler and then circulated through radiators or underfloor heating systems. This option may initially be more affordable because it has fewer parts and an easier installation procedure.
In contrast, a two-circuit boiler provides the household with the convenience of hot water and heating all at once. Larger households or those with higher hot water demands may find this dual functionality especially helpful. Users can enjoy hot water on demand without compromising the heating system and have more control over temperature settings thanks to separate circuits for heating and hot water.
An important thing to think about is energy efficiency. The two-circuit boiler may provide more precise control over energy usage because of its separate heating and hot water circuits, even though both types of boilers can be energy efficient when installed and maintained correctly. Over time, this may lead to potential energy savings, particularly in homes where hot water and heating needs change during the day.
The choice between a two-circuit boiler and a single-circuit boiler with indirect heating ultimately comes down to a number of variables, including household size, hot water usage patterns, financial constraints, and preferences for simplicity over versatility. Through meticulous evaluation of these factors and expert advice from heating specialists, homeowners can choose the solution that best meets their requirements and offers dependable warmth and comfort for an extended period of time.
