Patterson-Kelley continues to push the limits of technology by increasing turndown, with emphasis on system efficiency, reliability, and serviceability. By using a mechanical method to achieve higher turndown, we eliminate the need to add excess air. Adding excess air can reduce the dew point of the flue gas and adversely affect efficiency. The MACH condensing boiler is now available with 10:1 mechanical turndown capabilities for natural gas models C750, C900, and C1050. Benefits include flexibility to match input to building load; better control over temperature differential between return water and exhaust temperature; perfect for new installation and retrofit projects; simple boiler maintenance, and available for natural gas application.