GSW Condensing tankless gas (powered by Takagi)

This is GSW's Takagi-powered condensing tankless line. Unlike a storage tank, it only heats water when it is needed, so there is no standby heat loss. Condensing tankless heaters use a secondary heat exchanger that uses exhaust to pre-heat the water before it reaches the primary exchanger, which GSW says results in higher efficiencies; the line is published with a Uniform Energy Factor of 0.93.

The published feature set includes a power direct vent design, a commercial-grade copper primary heat exchanger that GSW says is more resilient against erosion, and a Type 316L stainless steel secondary heat exchanger to protect against corrosion. Venting is flexible: ULC S636 approved PVC, CPVC or polypropylene pipe, or Category III/IV stainless steel venting, can be used. GSW also lists internal freeze protection and multiple safety features, electronic ignition so there is no pilot light, and the ability to be used in residential hydronic heating applications. The unit takes significantly less space than a tank-type water heater and carries an industry-leading 15-year heat exchanger warranty when used in residential applications.

The line is documented here at family level because per-model inputs, flows at temperature rise and Canadian availability sit in the linked spec sheet, which is the source used before any model row is published. The installation manual, service manual and residential warranty sheet are linked alongside it. Whether CANRO supplies a specific model for a project is confirmed at consultation, and CANRO names GSW among the brands it services on its own pages.