Condensing boilers and water heaters operate at the highest efficiency. Any gas fired appliance rated above 85% efficiency will transfer heat so efficiently the flue gas will be cool enough to fall below the dew point and the gas will “condense” back into a liquid. This condensation picks up the products of combustion which is very acidic. Therefore the boilers required material of construction must be robust enough to handle and operate in this environment. Hydrotemp offers several solutions to your design needs.