The NCB Series combi-boilers are condensing combination boilers capable of delivering plentiful hydronic heat and unlimited domestic hot water for large homes. The combi-boilers are offered in three models: the NCB-180, NCB-210 and NCB-240. They are uniquely designed for ease of installation, said the company. With the capability to use ½-inch gas connections and 2-inch polyvinyl chloride (PVC) venting, contractors can retrofit the units. The dual venturi system allows for easy field convertibility from natural gas to propane (LP) operation and the orifice for LP conversion is included. The combi-boilers operate at a minimum gas pressure of 3.5 inches of water column, allowing for easy conversion from natural gas to LP. Low exhaust gas temperatures allow use of PVC, chlorinated polyvinyl chloride (CPVC), ULC S636, and polypropylene vent systems, reducing installation time and costs. The system can use 2-inch venting for up to 60 feet, or up to 150 feet with 3-inch venting. The units have dual inputs of up to 120,000 Btuh for heating and 199,000 Btuh for domestic hot water.