Inventia se refera la termotehnica si poate fi utilizata in sistemele de incalzire cu apa si pentruincalzirea apei menajere. Cazanul de incalzit (varianta I) contine un corp cu manta de apa, o camera de ardere dotata cu arzator, racorduri de debitare si evacuare a apei, elemente cave orizontale cusuprafete de incalzire prin convectie, care sunt cuplate cu mantaua de apa si formeaza un canal de gaze in forma de labirint, unde in partea inferioara este amplasat un racord pentru gaze de ardere, dotat cu o clapeta, o despartitura cava verticala cu suprafete de incalzire prin convectie, cuplata cu mantaua de apa, un element cav, dotat cu o suprafata de incalzire prin convectie inclinata si cuplat cu mantaua de apa, schimbatoare de caldura cu tevi, cuplate cu mantaua de apa si amplasate pe toata lungimea canalului de gaze si in camera de ardere, guri pentru evacuarea funinginii si o supapa de siguranta, care sunt cuplate cu canalul de gaze, si un incalzitor de apa menajera. Cazanul suplimentar contine un sistem automatizat de dirijare sicontrol a regimului de lucru al cazanului, care include un bloc computerizat, conectat cu un bloc de control, la randul sau, conectat cu un bloc al arzatorului, un bloc de distribuire a apei, un blocde incalzire a apei menajere si un bloc de securitate. Blocul arzatorului este conectat cu clapeta dirijata la distanta si cu elemente de asigurare atirajului in canalul de gaze, cu care este dotat racordul pentru gaze de ardere, toate blocurile sunt conectate intre ele si elementele de lucru ale cazanului, precum si la un bloc de alimentare, iarblocul computerizat este conectat la un bloc computerizat la distanta cu bloc de alimentare. In cazanul de incalzit din varianta II, camera de ardereeste dotata cu un reflector director, cuplat cu mantaua de apa, si este amplasata in partea superioara a canalului de gaze. Cazanul de incalzit (varianta III) contine doua camere de ardere, una amplasata in partea inferioara a canalului de gaze, cealalta – in partea lui superioara, si doua racorduri pentru gaze de ardere, unul amplasat in partea superioara a canalului de gaze, iar altul – in partea inferioara a camerei de ardere inferioare. Rezultatul inventiei consta in intensificarea transferului de caldura prin majorarea timpului de contacta gazelor de ardere cu temperatura mai mare cu suprafetele de incalzire prin convectie si a diferentei de temperatura a agentilor termici, automatizarea regimului de lucru si control al cazanului, simplificarea constructiei, reducerea volumului de metal, folosirea diferitor feluri de combustibil fara a schimba arzatoarele si a mai multor surse de energie la incalzirea apei menajere.The invention relates to thermotechnics and can be used in water heating systems and for domestic water heating. The boiler (variant I) contains a body with a water jacket, a combustion chamber equipped with a burner, connections for cutting and draining the water, horizontal cavity elements made of convection heating, which are coupled with the water jacket and form a maze-shaped gas channel, where at the bottom is located a flue gas connection, equipped with a flap, a vertical hollow partition with convection heating surfaces, coupled with the water mantle, a hollow element, equipped with a heating surface by inclined convection and coupled with the water mantle, heat exchangers with pipes, coupled with the water mantle and placed along the entire length of the gas channel and in the combustion chamber, mouths for drainage and a safety valve, which are coupled with the gas channel, and a domestic water heater. The additional boiler contains an automatic control system for the control of the boiler operating mode, which includes a computerized block, connected with a control block, in turn, connected with a burner block, a water distribution block, a heating block. of domestic water and a security block. The burner block is connected with the remote-controlled flap and with elements for securing the draw in the gas channel, with which the flue gas connection is equipped, all the blocks are connected between them and the working elements of the boiler, as well as to a power supply block. , the computer block is connected to a remote computer block with power supply block. In the heating boiler of variant II, the combustion chamber is equipped with a directional reflector, coupled with the water jacket, and is located in the upper part of the gas channel. The boiler (variant III) contains two combustion chambers, one located in the lower part of the gas channel, the other - in its upper part, and two connections for combustion gases, one located in the upper part of the gas channel, and the other - in the lower part of the lower combustion chamber. The result of the invention consists in intensifying the heat transfer by increasing the contact time of the combustion gases with higher temperature with the heating surfaces by convection and the temperature difference of the thermal agents, the automation of the working regime and control of the boiler, simplifying the construction, reducing the volume of heating. metal, using different types of fuel without changing the burners and several energy sources when heating domestic water.