For preparing hot water. Designed to connect one heat source; tank and heat exchanger made of carbon steel; the heat exchanger is coated with an organic Polywarm coating, which has no negative effect on drinking water. insulated with 50 mm of ecological polyurethane foam insulation; thermal conductivity 0,023 W/mK; heat loss 1,46 kWh/24 hours; integrated magnesium anode.