The 540H is well suited for residential/commercial applications such as small restaurants and beauty salons. Utilizing HRS35 copper alloy for the heat exchanger tubing, the 540H is also suitable for heavier-residential usages such as space heating or domestic recirculation systems. Remote control included as a standard feature. Indoor models are certified up to 10,100 ft. altitude. Thicker heat exchanger drum and utilizes HRS35 (heat-resistant) copper for the heat exchanger tubing. Provides a variety of installation options: outdoor and direct vent. Includes a pump control port, ensuring efficient operation of all circulation pumps. Complies with Ultra-Low NOx regulations and meets the energy efficiency requirements of ASHRAE 90.1b-1992. Easy-Link System capable up to 4 units. Multi-Link System capable up to 20 units.
The ATO-540H-N tankless water heater uses up to 199,000 BTUs of natural gas to deliver a max flow rate of 10 GPM. It utilizes condensing technology to achieve an Energy Factor of 0.95, and is ENERGY STAR® qualified. This model meets Ultra-Low NOx emission requirements, and comes with a 15-year limited warranty.
The comprehensive line of A. O. Smith tankless water heaters provide hot water on-demand.
• A hot water tap is opened
• The opened tap allows water to flow through the water heater. An internal water flow sensor detects this flow
• Upon flow detection, the flow sensor sends the activation signal to the computer board
• The computer automatically ignites the burner
• As water flows through the heat exchanger, it absorbs heat from the burner
• By the time the water exits the heater, it has reached the designated set temperature
• When the hot water tap is closed, the water heater automatically turns off
|Limited Heat Exchanger Warranty:
|Limited Parts Warranty:
|Water Connection Location:
|Water Connection Size:
||HRS35 Copper Alloy
|Secondary Heat Exchanger:
|Dimensions & Venting
||PVC, CPVC, PP, ABS, SS
Dual Heat Exchanger
The primary heat exchanger is constructed of commercial-grade HRS35 copper, which is stronger than standard copper and more resilient against erosion. Condensing models feature 316L stainless steel secondary heat exchanger, providing additional protection against corrosion.
A. O. Smith tankless water heaters take up much less space that your conventional tank-style water heater. With no tank to steal valuable storage space, our wall-mount design allows for additional storage and flexibility.
Includes freeze, overheat, surge protection and troubleshooting diagnostic codes.
Endless Hot Water
The comprehensive line of A. O. Smith tankless water heaters are an excellent whole-home water heating solution that supply endless hot water.