The heater has been designed for the installation in small space, and makes a valid solution for kitchen and toilet. The insulation of water heater is realized in cellular rigid polyurethan to high density injected at warm for minimize the loss of heat. The external cover is a careful design of workmanship. It is made in high polystyrene (model 10 liters) or in metal sheet painted white (models 10-15-30 liters). The innter tank is protected by resins polymerized at temperature of 250°.