As one of North America’s first companies offering a condensing gas boiler, NTI has a proven record of delivering highly efficient and reliable boilers for the residential and light commercial market. Now on its ninth-generation boiler, NTI has consistently enhanced and improved its products while expanding its offering to consistently deliver industry-leading technology. Continuous innovation, attention to customer need and leading edge technical support underpin its success.

Residential gas condensing boilers

With the industry’s broadest range of high-efficiency gas boilers, NTI offers a tremendous selection of technologies, features and price points to meet any need.


NTI continues its tradition of creating innovative and unique solutions with its new combi-furnace. Offering the combination of Forced Air and Hydronic heating, plus Domestic Hot Water in a single system, it reduces installation costs and environmental impact while delivering top thermal comfort and performance.

Commercial gas condensing boilers

NTI has developed a range of high-efficiency commercial gas condensing boilers utilizing multiple heat exchanger technologies, offering a choice of fire tube and water tube options, ranging in power from 300 to 2400 MBH (88 – 700 kW) residential and commercial use.

Water heaters systems

NTI delivers high-quality and efficient water heating solutions with a full line of stainless-steel indirect water heaters suitable for residential and commercial applications, and a line of high-efficiency condensing gas water heaters designed for high-volume water heating applications.