Agroresurs elaborated and proposes consumers a new series of boilers Danko with capacity of 8-24 kW equipped with the device Kolchuha used for water treatment by pulse dynamic electromagnetic field due to which water loses its property to form solid scale for a certain period and solves existing water stone. The boilers of this series do not need any additional maintenance, any expenditure materials, they consume a small quantity of energy, exclude application of chemical reagents, that is why they are ecologically safe. The device “Kolchuha” is mounted inside the boiler “Danko” on the outlet pipe of the heat exchanger, that is why the above boilers do not differ from their analogues in their exterior aspect. The principle of “Kolchuha” operation is based on use of electromagnetic modes of frequency 1-20 kHz with radiation capacity not more than 5 Wt. The distinguishing feature is a constant change of oscillations of frequency of electromagnetic radiation which produces resonance while salts structure is being formed.