NCB-E Series combi-boilers from Navien are capable of delivering plentiful hydronic heat and unlimited domestic hot water for large homes. They are offered in four models: the NCB-150E, NCB-180E, NCB-210E and NCB-240E. The NCB-240E model delivers the high combined heating capacity and domestic hot water capacity, heating up to 120,000 Btu/h and DHW up to 199,000 Btu/h. It offers easy installation with 1/2-inch gas connections and 2-inch polyvinyl chloride venting. 800-519-8794; www.navieninc.com.