A Better Solution Than Tankless Coils - The popularity of FlatPlate heat exchangers lies in their small size and highly efficient heat transfer surface. The performance of the brazed heat exchangers make them ideal for domestic hot water heating, radiant floor, snow melt and swimming pool heaters. By setting up the brazed plate as an on-demand zone in the boiler system, an on-demand BIASI boiler only fires when there is a call for heat. This provides huge savings in the spring and summer, as a traditional boiler with a tankless coil must remain at temperature year-round to be ready for even a small demand for domestic hot water.