Weil-McLain’s line of high-efficiency gas boilers includes the Evergreen, Ultra Series 4, GV90+ cast iron boiler and AquaBalance Series 2. All operate with natural or propane gas and feature the latest hydronic heating technology for heating comfort and energy-saving performance. The Evergreen stainless steel condensing residential boiler features an AFUE rating of 95% and is available in six sizes, ranging from 70 to 399 mBh input. The Ultra Series 4 boiler features a heat exchanger with a nanotechnology coating that protects the unit from buildup in the heat exchanger. The GV90+ high-efficiency cast iron boiler offers an AFUE rating of 91% and is available in four sizes. The AquaBalance Series 2 unit features an energy efficiency of 95% and combines high-efficiency space heating with the convenience of on-demand domestic hot water. 855-248-1777; www.weil-mclain.com.