Combined and separate boilers for heating on wood and electricity

In terms of home heating, having a dependable and effective boiler is crucial. A common choice for heating systems is a hybrid boiler, which functions using both electricity and wood fuel. Separate boilers for electricity and wood, however, also have benefits of their own. The differences between combined and separate boilers will be discussed in this article, along with tips on which one might be best for your house.

The ability to heat your home with both wood and electricity is a convenient feature of a combined boiler, sometimes referred to as a dual-fuel boiler. Because of its adaptability, you can benefit from both fuel sources. For instance, if wood is easily accessible, you can use it; otherwise, you can use electricity if you need a quick and practical source of heat. For individuals who desire the freedom to select their heat source according to availability, affordability, and convenience, combined boilers are frequently viewed as a workable option.

Separate boilers for wood and electricity, however, also have some notable benefits. You have specialized systems for every fuel source when you have separate boilers, which can increase efficiency and dependability. For example, if properly maintained, a wood boiler can be extremely efficient and lower your heating costs significantly—especially if you have access to free or inexpensive wood. Comparably, an electric boiler can serve as a dependable fallback choice, guaranteeing that you will always have access to heat—even in the event that wood is scarce.

The decision between a combined boiler and separate boilers ultimately comes down to your personal requirements and tastes. Which option is best for you will depend on a number of factors, including cost, convenience, reliability, and fuel availability. To assist you in making an informed choice for your home’s heating system, we’ll examine the features and advantages of combined and separate boilers in more detail in the ensuing sections.

The use of combined boilers

Not so long ago, heat generators powered by different sources of energy began to appear. "Two-fuel" gas boilers have been known since the USSR era; to convert from gas to wood, firewood in these boilers had to be removed using a burning device. More importantly for consumers, solid fuel is now mixed with electricity in modern heating units in addition to gas. A homeowner who chooses to purchase a heating boiler instead of using electricity and firewood makes multiple decisions at once:

1. Applies two energy carriers alternative to natural gas for heating at once.
2. Excludes the emasculation of the premises of a private house, when the contents of the fuel are completely burned, and a new portion of coal or firewood is not loaded.
3. Increases the ease of operation of water heating, since getting up in the middle of the night and running to the boiler room is no longer required.

Modern combined heat generators are built with an automatic feature that activates electric heating as soon as the water in the boiler tank starts to cool. It is impossible to make the opposite transition to burning wood without the home’s owner’s help.

The principle of operation of an electric boiler

This type of heater’s construction is akin to that of a conventional solid fuel boiler, with the following primary components:

• combustion chamber (fuel), where logs and coal are loaded;
• Outside, it is washed by a coolant, enclosed inside a water shirt;
• heat exchanger of a heat -tube or water tube type, where combustion products give most of the heat to water before ejecting out through the chimney;
• The grate is at the bottom of the fuel, and under it there is a ash chamber;
• The firebox and ash -bearing are equipped with doors;
• To change the intensity of combustion in the heat generator, a mechanical traction regulator or a fan – an air injection (if manual control of the air damper is not provided).

The design of a water shirt, which has a space designated for the installation of a block of tubular electric heaters, or heating elements, is different amongst household combined heating boilers. The element’s heating component is submerged in coolant, and its contacts are exposed and linked to the control panel’s cable.

The following is the algorithm that controls a solid fuel heater with electric heaters:

1. The boiler is prompted and heated as usual. While firewood is combined, the temperature of the coolant supports a mechanical thermostat or the fan together with the sensor, and the heater is inactive.
2. After burning the contents of the fuel, the water in the system begins to cool down, which registers the temperature sensor. When the coolant cools to a certain point, the heating element (one or several) will turn on at the signal of the sensor. From this moment, the boiler switches to electricity.
3. After loading the next portion of solid fuel, the coolant is heated from the combustion chamber, and the electric part is automatically turned off until the next cooling.

By switching between regimes, you can make sure that the water is heated continuously, which is something that private home occupants need for comfort.

Pros and cons of universal heat generators

You receive the following benefits when you install a combined boiler for firewood and electricity heating in a private home:

1. Thanks to built -in heating heating, water heating will continue to function after attenuating the main furnace. This will save the house warm, and during your absence will not let the pipes and heating radiators defrost.
2. Comfort. Support for heating the system with electricity will save you from night campaigns in the boiler room for laying logs.
3. If the electricity accounting is carried out according to a multi -tariff scheme, then in addition to convenience you will receive savings from the work of the heating elements at night.

The combined boiler’s electric heaters are only intended to keep the water temperature in the system; they cannot completely replace the burning of solid fuel. The manufacturers’ inadequately powered heating unit installed on TT Kotla is the cause.

For example, the same electric heaters with a 6 kW heat transfer are found in all Kupper units, manufactured by the well-known Russian brand "Teplodar" and with capacities ranging from 9 to 20 kW.

It is safe to say that this combined heat generator feature is what causes their drawbacks. The low-power heater (the same Cooper is 9 kW with 6 kW hee) that was bought for a small space (up to 100 m²) is the exception. Since heat transfer from electricity is equivalent in this instance to burning firewood, heaters can fully heat a modest house in temperatures as low as –5 °C in the yard.

One more crucial point. A three-way valve should be used to connect a combined boiler of firewood and electricity to the water heating system, just like a traditional solid fuel heater does, as the diagram below illustrates. During traction, the fuel is shielded from the damaging effects of condensate by the small circulation circuit contour.

A node with a three-way mixing valve is useless if the heating elements’ power is sufficient to raise the coolant’s temperature to +55 °C or higher, which prevents condensate from ever forming in the combined boiler’s combustion chamber. Actually, a small circulation circuit circuit is still required, if only in the event that one of the heating plants breaks down or the electricity is turned off.

There are additional drawbacks to heating a private residence with electricity and firewood from a single boiler:

1. The heater block takes the useful volume of the fuel to the detriment of the duration of the combustion from one load.
2. The operation of the unit depends on the stability of the power supply.
3. The prices of combined products are higher than classic solid fuel boilers.
4. The efficiency during the operation of electric heaters is reduced by 2-5% due to the air flow passing through the cooled firebox. The reason is the constant traction in the chimney, which makes the air go out of the rooms through the fuel tract into the chimney and cool the water heater.

It is preferable to consider an alternative method of heating the building, such as installing two independent heat sources and properly connecting them to the heating system, in order to completely replace natural gas with electricity and firewood.

Selecting between combined and separate boilers can have a significant impact on how effectively your home is heated. With combined boilers, you can switch between energy sources based on availability and cost. They are versatile and economical because they use both wood and electricity. Conversely, individual boilers for wood and electricity offer convenience and dependability, guaranteeing a steady supply of heat at all times. It’s imperative to weigh the advantages and disadvantages of each choice when choosing a heating solution for your house.

Connection of boilers on wood and electricity

You will definitely pay more for the purchase, installation, and strapping of two individual units than for a single combined heat generator. However, by utilizing this option, you receive complete heating using two energy carriers, essentially operating in automatic mode.

Reference: Since this is the most practical way to fill the house with wood, solid fuel and electric boilers work together quite a bit in non-distributed private homes in the Russian Federation. Gas and firewood are a common combination as well; the so-called multi-fuel boilers, which we will discuss in a separate article, come in third.

Our two heat sources are an electric auxiliary unit and a firewood (coal) boiler. If you choose the latter, you can utilize any of the three types of electric boats that are available on the market:

• traditional tennoy with built -in circulation pump and control unit;
• electrode with a remote control panel;
• induction with a separate remote control.

We won’t go over the benefits and drawbacks of each kind of electric vehicle here; that is the subject of a different article. Here, we’ll demonstrate how to connect boilers for electricity and firewood using diagrams so that the second will automatically insure the first. First, let’s discuss joint strapping between a heating unit and a piece of wood:

Reference: A gas wall boiler installed in the location can be connected in tandem with the scheme that is being presented.

This is how the system’s architecture appears:

1. TT boots are inactive and its circulation pump is disconnected. Heating devices receive heat from an electric boiler focusing on a room thermostat, where you set up the desired temperature. So that the coolant does not move in a circle through a parallel ring, 2 check valves are involved in the circuit.
2. You melted a solid fuel unit. For some time it will begin to gain temperature, and the water will circulate in a small circle, directed by a three-way valve with a thermogram. The pump will turn on at the command of the overhead thermostat installed on the supply pipeline.
3. When the coolant in the small ring heats up to 55 ° C, the temperature sensor of the thermogram standing on the reverse line will work. The three -way valve will open and heat will go to the heating system.
4. The electric boiler will turn off the heating at the signal of the indoor thermostat and will go to the on -duty mode.
5. After the burning of solid fuel, the water is in the system, and behind it the air in the premises will begin to cool down. The TT-Kotla thermostat of the TT KOTLA will “see” that the coolant has cooled down and stop the pump.
6. Когда температура в доме снизится до выставленного вами значения, комнатный терморегулятор вновь задействует электрокотел.

Crucial! You must select a more powerful wall heat generator for a solid fuel heat source because the internal circulation pump of the wall heat generator cannot be turned off. Generally speaking, a 0.6 bar pump is sufficient (an electric boiler typically requires 0.5 bar). Second moment: place all overhead sensors and thermostats on metal pipes. These pipes will lie on polypropylene or metal-plastic.

In this video, our expert Vladimir Sukhorukov will explain in detail how to connect the electric and solid fuel boiler correctly:

The circulation pump and filter for induction and electrode heat generators are not included in the package; these items must be purchased and installed separately. This is the only distinction in the connection diagram for this kind of heating; as the circuit illustrates, the pump unit only needs to be connected to the network via the control cabinet in order for the electric boiler to turn off the room thermostat.

Primary and secondary rings are used to connect the wood and electric boilers for joint operation if a private home’s heating system consists of multiple circuits, such as warm floors, indirect heating boiler, and radiators on separate floors. This type of binding’s operation is explained in principle here.

Using TT KOTLOV long-burning

Boilers, both combined and single-acting, are examples of large-scale electrical equipment that not every homeowner is technically capable of connecting. The dedicated power limit is only available to private homes, which is the cause. The local power supply networks’ throughput determines the size of the limit, and the suburban cottage owner is unable to increase it.

There is only one option when there is no natural gas available on the property or when accessing the highway is expensive: either purchase a boiler that runs on wood and coal coal or build one yourself. At a traditional TT KOTL, one loading takes three to six hours to complete, so the owner must work close by using a stoker. Not every heater offers as much fuel as others do, and a minimum of eight hours is a comfortable gap between bookmarks.

The issue lies in the fact that unscrupulous manufacturers mislead unsuspecting consumers by referring to their products as long-burning boilers. Among other heat generators, you can identify the right one by looking for the following indicators:

• with the same power, the boiler with a large supply of the course is equipped with an increased volume fuel (from 100 l) and differs in size;
• The passport indicates the duration of burning from 8 hours (on wood);
• For convenience, the unit is equipped with an additional loading door.

A different topic publishes comprehensive details on these heat generators and suggestions for selecting them.

Conclusion

As a conclusion, we will provide a few basic guidelines for setting up a private home’s comfortable heating system using electricity and solid fuel:

1. Combined boiler on wood and electricity is one of the best options for a summer or residential house of a small area. In the cottage on 2-4 floors, Tena can only protect the system from defrosting.
2. In a country house, more than 100 m², it is appropriate to use 2 separate heat sources with a correct strapping.
3. Когда электроэнергия подается с перебоями либо лимит мощности не превышает 5 кВт, с электричеством не стоит связываться вовсе. Find the opportunity to purchase a heat generator of prolonged burning, although at a price it will cost more than usual.
4. Do not discard the ability to arrange air heating on firewood from the furnace if it is already bought or built. As insured at night, put electric convectors or thermal tanks equipped with thermostats.

Finally, in Scandinavian countries, where homeowners are accustomed to experiencing crackling frosts, wooden houses are frequently heated. Regarding this—the previous video:

Several factors determine whether you should use a separate boiler or a combined boiler to heat your home with electricity and wood. A combined boiler could be your best bet if you can get free or inexpensive firewood and want a greener solution. Depending on availability and price, you can alternate between wood and electricity.

However, if efficiency and convenience are your top priorities, a separate boiler system might be preferable. Separate boilers provide more control over each heating source, possibly resulting in lower energy bills and easier maintenance, even though they may initially cost more.

Whichever option you select, safe and effective operation of your heating system depends on correct installation and ongoing maintenance. To find the best solution for your house given your unique needs and circumstances, think about speaking with an expert.