These boilers are intended for central heating systems of smaller residential and family houses, premises and smaller production units. Solid fuel, fuel oil or pellets are used as a fuel (with addition of the burner on fuel oil or pellet and operating controls). They are intended for operation temperature regime of 90/70 oC. Firebox and convection part of the boiler are made of the quality boiler plate with welding technology. Cleaning of the boiler is simple and easy, and boiler cleaning kit is delivered together with the boiler. Firing The firebox door dimensions to accommodate large fuel pieces. Boiler has good thermal insulation with hard pressed mineral wool in quality sheet housing. Installation and putting into operation are simple and connectors are standard. Boilers are attested by the Faculty of Mechanical Engineering in Banja Luka. Nominal power of furnace is achieved with lignite "Stanari" which is of small thermal power (about 11 00 kJ/kg). Boilers are designed, produced and tested according to the Europeans standard EN303-5.