Boiler piping in a private home

Wrapping variants of solid fuel boilers for heating in a private house

boiler, piping, private

Special strapping of the solid fuel boiler can provide the comfort in the house. It serves to ensure the safe operation of the heating system. In addition, acts as a guarantor in order to save fuel consumption. Many newbies can’t tie the solid fuel boilers properly. As a result, the device stops working normally. Accordingly, the power is significantly reduced.

Natural circulation

For the gravity flow system is characterized by complete energy independence: its work provides the atmospheric pressure. Instead of a cumbersome safety group in the strapping of a single-circuit boiler, the presence of an expansion tank is enough. A discharge should preferably be installed at the outlet before the boiler heat exchanger: this enables the water to be completely discharged into the sewer or drainage well. Usually such a need arises in case of a long vacation, or when the gas supply is interrupted. As a result, the system is protected against defrosting.

The individual components of the system are arranged as follows:

  • It is recommended to install the tank above all other elements.
  • The outlet immediately after the boiler must be positioned vertically (a slight angle is acceptable). The water heated in the heat exchanger rises via the overflow pipe to the upper outlet point of the supply.
  • It is important to maintain a constant downward slope when installing the fill after the cistern. As a result, the cooling water will return by gravity: air bubbles will be able to escape inside the expansion tank.
  • The boiler must be lowered as low as possible. The best place to place the heater. a pit, basement or cellar. Due to the difference in height between the heat exchanger and heating devices provides the proper level of hydraulic head, providing water circulation in the circuit.

Some features of the arrangement of the inertial heating system:

  • 32 mm is the right size for the inside diameter of the outlets. If plastic or metal-plastic pipes are used, the outer diameter is equal to 40 mm. thanks to the large cross-sectional area, a minimal hydraulic head compensation is achieved, due to which the heating medium is transported.
  • The gravity system sometimes includes a pump: but this does not mean that the circuit loses its energy independence. In this case, the pump is not mounted in the gap of the filler, but parallel to it. To connect the individual taps a ball-type check valve is used, which is characterized by a very small hydraulic resistance. Also install a ball valve. In the case of stopping the pump produce bypass closure, which keeps the loop with natural circulation.

Pattern Varieties

It is required to study the types of techniques, before you can properly tie a heating boiler. The design may differ depending on the type of unit and how the flow is organized. Heating circuits are mounted closed and open. Circulation of energy carrier is either forced or gravitational. With the open method of installation an expansion tank without an upper cover is installed. It combines several functions:

  • Allows you to compensate for the evaporated water refill;
  • adjusts the volume of the energy carrier in case of overheating, accommodating the excess;
  • removes airlocks if the unit is installed with an even slope from the tank to the unit’s heat exchanger.

No pump is required for operation, so the circuit functions silently.

In this video you will learn how to connect the boiler:

With the closed method there is no connection to the atmosphere, and the circuit works under pressure. The problem with the design is that overheating increases the pressure, so pipes or appliances can rupture. An important element of the system is a membrane expansion tank, which protects the circuit from hydraulic shock. It is made of strong metal to withstand the pressure.

The design has two s, looped one to the other and separated by a rubber heat-resistant partition. The first one moves the coolant, and the second one has some gas (nitrogen or accumulated air). Water heats up, enters the expansion tank and flows through the diaphragm. Once cooled, the gas pushes the mass back into the system. Polypropylene or metal pipes are used for heating under this scheme.

There are several methods of strapping the boiler

Differences between the open method and the closed method

Before choosing a heating option, you need to know some features of the two designs. The open and closed circuits have differently positioned expansion tank. There are also other distinctive features. They are as follows:

  • In the open version of the cistern is placed in the highest area of the circuit, and in the closed method for the placement of this element is not strictly limited, it can be cut in near the generator or make a wall
  • in a closed volume, due to the absence of contact with air, the service life of the contour elements is prolonged;
  • additional pressure in the closed scheme eliminates stagnant air and pushes the plugs to the outlet;
  • In an open ring, the pipes are placed under the slope to create a natural current, which is inconvenient in some cases;
  • it is required to take into account the elevation, constriction areas, bypasses and turns, connection points in the case of open heating;
  • the diameter of the manifold in an open loop is always larger than in a closed system, thick pipes are difficult to hide in the interior, requires constant monitoring of the liquid level due to evaporation;
  • in a closed circuit, you have to choose a place to install the pump in order to reduce the noise level during operation.

Gravity circulation

Heat transfer fluid moves naturally in the units, and forced action is connected when it enters the circuit.

In this model the water moves according to the physical laws and is conditioned by the different density of hot and cooled medium. No electricity is used and there is no automatic regulation device. The scheme is more often developed for small buildings. In the gravitational concept of the open type piping of any solid fuel unit includes:

  • collector to disperse water in the area immediately after the boiler;
  • an open expansion tank, the volume of which is equal to 10% of the circuit capacity;
  • shut-off screws at the outlet and inlet for disconnecting the heat exchanger in case of repair, no need to drain the medium.

An expansion vessel is installed in the upper area after the collector. It provides a tap to fill the system with water, and below mount a screw to drain the energy. The boiler is placed in the lower area of the circuit. Height difference allows water to move by gravity.

Before wrapping it is necessary to know about gravitational circulation

forced system

The method gives the necessary head with the help of electric pumps. This type of circuit is convenient in operation, t. к. Control is automated with a constant supply of energy and allows the temperature to be set separately for each room. With a properly arranged boiler house piping scheme, benefits are obtained in the form of:

The pump in the boiler harness scheme is placed in front of the unit in the direction of water movement, the heating in this point is minimal. The pump is installed in parallel to the spill area. A ball valve or check valve with small resistance is mounted between the tapping points.

With proper piping, there will be several advantages

During the operation of the pump the piping between the connections is closed. After the supply is completed, the ball valve is back in the operating position, and the heating system operates on the gravitational principle. The technique has disadvantages noted:

  • the complexity of the design;
  • mandatory performance of balancing of the elements;
  • Periodic maintenance and repair is expensive;
  • the price of spare parts is high.

Number of circuits

In schemes of heating boilers with an additional connection of hot water, the unit is connected with the moisture supply system for domestic use. But the single-circuit generator can also heat the liquid by adding a secondary heat converter. Most often install a metal canister of stainless steel with a supply pipe.

Single-circuit unit is characterized by a simple principle of operation. Natural draught is required for operation, so it is connected to the chimney during installation. Boiler is placed in the service unit, t.к. ambient air is used in operation. These actions will prevent an explosion from occurring and keep the occupants of a private building safe.

Two-circuit unit differs in the number of functions performed. It simultaneously maintains the temperature of the water in the system and heats the liquid in the tank for domestic use after contact of the energy carrier with the secondary heat exchanger. The heat is given directly, the energy carrier is not heated when the boiling water is discharged, and simultaneous operation of the two lines is not possible.

To obtain a large volume of heated water, columns and single-circuit scheme are combined. Two-circuit unit is not used in constructions with natural movement of water. When stopping heating, the liquid cools quickly, and the subsequent heating takes a long time.

Choice of pipes

To connect the gas boiler and perform wiring, it is recommended to use metal-plastic or PP-pipes. They are not inferior to copper or galvanized, installation is quite simple, the cost is lower.

Distribution for heating batteries is made with metal-plastic pipes with the use of press-fittings or polypropylene, with aluminum reinforcement. The disadvantage of press-fittings. sensitivity to the quality of installation: at the slightest inaccuracy of placement leakage occurs. Polypropylene pipeline under the influence of temperature above 50 ° C extends. For installation of “warm floor” suitable and metal-plastic, and polyethylene pipes.

The process of strapping the boiler with your own hands

In order to make the strapping of the standard scheme of heat supply, in order to avoid emergency situations, apply the obligatory steps in a strict sequence, for example, for a solid fuel boiler.

Algorithm of step-by-step assembly of a single-pipe scheme:

  • Free the unit from the packaging.
  • For a small boiler room installation work is carried out outside, starting with the installation of the furnace door and ash pan.
  • All auxiliary equipment that comes with the kit is installed separately: smoke pump, pressure gauges, safety valve, thermometers, check valve, pump. Automatics and fan are the last to be installed.
  • Take the boiler to the furnace room and place, depending on the power, either on the floor or on the foundation.
  • The flue gas outlet pipe must be coaxial with the chimney.
  • Fix the boiler structure firmly to the foundation, without any distortions.
  • Fan, chimney and safety automatics are installed.
  • The final stage. the connection of the unit to the heating system.

What to choose

It is believed that the choice of pipes PN25 should correspond to the cost of boiler equipment. For a cheap wood burning stove you can use Chinese pipes. But not the first encountered, but the ones that are made in China under license from one of the countries of the European Union, made of imported raw materials on original equipment. E.g. “BLUE OCEAN”.

For strapping two-circuit boiler polypropylene products from German companies “Wefatherm”, “Banninger” or Italian pipes from “Valtec” can be used. From the cheaper can be recommended quality polypropylene from the company “Ekoplastik. They are not capricious when installed and tolerate low temperatures very well. Of Turkish pipes for piping is suitable “Vesbo”.

Did you choose your own pipes for strapping the boiler?

What to buy and for what

Elements of the wiring diagram of the heating boiler in the maximum configuration include:

  • Expansion vessel.
  • Pump.
  • 8 taps (two each for pump, supply and return, and one each for cold water inlet and hot water outlet).
  • Fittings (American nuts, couplings, corners, tees).
  • Mechanical filters (2 pcs) and a softener (1 at the inlet to the boiler with cold water).
  • Gas valve and pressure reducer (for gas boiler).
  • Pressure relief valve (air vent).
  • A separate electric supply (for all boilers with electric parts as well as pumps).
  • Measuring devices.
  • Adapter from the boiler chimney to the house chimney (except for the gas turbine ones the chimney is included in the kit).
  • In some cases, blower fans and smoke exhausters may be installed if required by the project.

Depending on the boiler and the chosen scheme of the heating system, some elements may not apply.

Boiler strapping with maximum simplicity

We should separately mention the choice of material for the pipes. Plastic pipes are easy to install and are used everywhere. But sometimes the conditions of the project require the use of steel pipes. Today, this is due, in most cases, to the requirement of fire safety standards or fulfillment of technical requirements to ensure uninterrupted operation of heating. If so, it is necessary to specify where and what kind of pipes you can use according to the project. For example, part of the circuit in the boiler room can be made of metal in the boiler room itself, and in the residential/office space switch to plastic. Or all the piping to do metal, if it is a heating shop, a workshop and it is required by the project.

Boiler strapping method

  • Boiler installation.
  • Plumbing work for the connection of the boiler to the heating system consists of: connection of supply and return flow with the installation of a filter on the latter, installation of a filter and softener on the inlet of cold water (for charging the heating system), installation of a hot water tap.
  • Installing and checking the pump operation.
  • Connection of fuel source (gas, electricity)
  • Installation of the air valve.
  • Installation of the expansion tank.
  • Installation of control devices (manometers, thermometers, thermocouples, pyrometers)
  • Simulation of situations for triggering emergency shutdown systems.
  • Complete check of the heating system with the mounted boiler fitting.
  • Work acceptance.

Optional elements

What other elements can include strapping floor or wall boiler?

Heat accumulator

Metal or plastic tank with insulated walls. As its name suggests, it serves for accumulation of thermal energy.

  • When using a solid fuel boiler. Accumulation of heat allows you to increase the time between firing and operate the boiler at its nominal capacity (and therefore with maximum efficiency);
  • When heating the house with an electric boiler and a two-rate meter. At night, when the price per kilowatt hour of electricity is minimal, the boiler heats the water in the storage tank, and during the day the accumulated heat is used to heat the house.

Using a heat accumulator requires the presence of two circuits, at least one of which operates with forced circulation. The first ring connects the heat exchanger of the boiler and the tank, the second heat accumulator and heating appliances.

Connection diagram of the heat accumulator to the boiler and the heating circuit with recirculation.


Hydrostreamer with connectors for connecting multiple circuits.

In essence, it’s just a thick pipe with multiple inlet and outlet spigots. The function of the water heater is to synchronize the operation of several circuits with different coolant temperatures (e.g. radiators and underfloor heating).

The water temperature in the pipes of the underfloor heating is no more than 40 degrees.

Each of the circuits is equipped with its own pump and (in the case of a low-temperature circuit) a three-way valve, which provides recirculation of the coolant.

In some cases the heat accumulator performs the function of the hydrostatic expansion valve.

Inside the tank slowly circulating water is divided by temperature: the hottest (and least dense) coolant collects in the upper part of the tank, the coldest in the bottom.

By withdrawing water from pipes located at different heights, you can get any temperature in the range from the boiler supply temperature to room temperature.

The photo shows the connection of the accumulator to the multi-temperature DHW and underfloor heating systems.

One of the problems of connecting the radiators in series is the dispersion of the temperature between them. Radiators on the flow is always hotter than the batteries on the return, which leads to uneven heating of the rooms in the house.

The manifold allows you to connect multiple convectors, radiators or underfloor heating circuits in parallel. Each branch of the collector is equipped with its own valve or restrictor, allowing independent shutdown and adjustment of devices.

Boiler indirect heating

Usually for heating DHW is practiced by using a two-circuit boiler with a flow-through heat exchanger.

However, this solution has a couple of unpleasant drawbacks:

  • Simultaneous operation of the heating and flow heater requires a large power reserve. If you have an electric boiler, and the house is allocated power of 10 KW you willy-nilly have to choose between warm rooms and hot showers;
  • Most instantaneous heaters do not allow for fine-tuning the output water temperature. Trying to take a shower or wash the dishes turns into a continuous battle with the taps.

Indirect water heater is a typical storage water heater, deprived of both problems. It is connected to the heating circuit and takes some of the heat from the heating medium.

In summer, circulation goes in a small circle between the boiler and the boiler.

If we talk about the peculiarities of the boiler unit of this type, the main thing is to connect to the electric power supply network. There are strict requirements here:

  • separately laid cable from the switchboard;
  • Installation on site of a serious security system: automatic circuit breakers, RCDs and others;
  • Accurate calculation of all elements of the connection, taking into account the power consumption;
  • Installation of the electric boiler, taking into account the requirements and provisions of the PUE.


The principle of the unit is simple. There is a tank in the construction, inside which an electric heater is installed. This can be a heating element, electrodes or an induction coil. Two pipes are connected to the vessel. One of them lets the water inside, while the other one is used to remove already heated water from the tank.

There are models on the market without circulation pumps and with them. The former allow you to simplify the bundling. But if the second one is installed, you can additionally buy a circulation pump and install it in the boiler wiring.

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