- ENERGY STAR® certified
- Continuous flow rate up to 10.0 GPM
- Primary commercial-grade copper heat exchanger is 25x better than stainless steel at heat transfer, stabilizing outgoing water temperatures quicker
- Secondary heat exchanger is made of 316L Stainless Steel to protect against corrosion
- Highly efficient condensing Ultra-Low Nox tankless water heater delivers up to .94 Uniform Energy Factor (UEF)
- Flexible power direct vent design allows for venting up to 100 feet using either PVC, CPVC, polypropylene or ABS Pipe (solid core)
- Common vent up to 8 units
- Includes a wall mount temperature remote controller and advanced diagnostics to simplify troubleshooting
- Safety features include exhaust & water temperature safety control, overheat cut-off fuse and air-fuel ratio (AFR) sensor
- 15-year limited warranty on heat exchanger in residential applications
The 540 series is well suited for residential use. Utilizing commercial grade copper alloy for the heat exchanger tubing, the 540 series is also suitable for heavier-residential usages such as domestic recirculation systems. Remote control included as a standard feature on all Outdoor models. Indoor models are certified up to 10,100 ft. altitude. Provides a variety of installation options: outdoor and direct vent. Complies with Ultra-Low NOx regulations and meets the energy efficiency requirements. Easy-Link System capable up to 4 units. The ATO-540H-N tankless water heater uses up to 199,000 BTU/hr of natural gas to deliver an endless supply of hot water for a 3 bath home in northern climates and up to a 4 bath home in southern climates (one shower head per bath). Utilizing condensing technology, this heater is extremely efficient with a Uniform Energy Factor of 0.95. With an industry leading 15-year limited warranty, the ATO-540H-N tankless water heater provides years of hot water through innovation and quality. A. O. Smith’s ProLine® water heaters are residential products built to commercial-grade standards and are only available for purchase through professional wholesalers and contractors.
