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A.O. Smith X3 - Residential 199,000 BTU - Natural Gas Tankless Water Heater - Outdoor
Model:
ATO-540HX3-N
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Recommended Accessories
Expert Recommended Accessories
Selected by Ken, our Expert
Required Accessories
9
These accessories are required to properly setup/install this product.
Optional Accessories
10
Features
Fuel
Natural Gas
Location
Outdoor
# of Showers
3.0
UEF
0.95
Energy Star Certification
Yes
- X3 Scale Prevention Technology
- With the patent pending technology, no annual descaling is required. With no scale buildup means the heater maintains like-new performance longer.
- Heavy Duty Heat Exchanger
- The primary heat exchanger is built out of copper, offering better heat transfer than stainless steel and designed to be more resilient against corrosion. A.O. Smith water heaters are built to last and save you money in the process.
- Multiple Safety Features
- A.O. Smith water heaters come with a long list of safety features standard. These include built-in freeze protection, overheat cutoff fuse, exhaust & water temperature safety control and an Air-Fuel Ratio (AFR) Sensor.
- Recirc Capable
- Tankless water heaters with X3 Technology are approved to work with an external recirculation pump and cross over valve.
- Ultra Low-NOx Emissions
- This A.O. Smith tankless water heater is designed to qualify for the most stringent Low-NOx standards. These standards coincide with SCAQMD rules and other air quality management districts.
- Product Includes
- Installation manual and owner's guide
- Temperature remote controller kit
- X3 cartridge
A.O. Smith continues to lead the way in residential water heating with close to 70 years of innovative hot water solutions. The ATO-540HX3-N condensing gas tankless water heater features X3 Scale Prevention Technology to last three times longer than other tankless models without X3 Technology. Complies with Ultra-Low NOx regulations and utilizes commercial-grade copper alloy for the heat exchanger tubing and are approved to work with an external recirculation pump and cross-over valve. Making this one of the most efficient heaters on the market.
California residents see
WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm..
For more information go to: www.p65Warnings.ca.gov
Specifications
ATO-540HX3-N
Overview
Product Category
Water Heater - Tankless
UPC
671657270162
General Information
Type
Tankless Water Heater
Product Line
ProLine XE
Product Category
Water Heater - Tankless
Medium
Medium
Medium refers to the substance that carries heat through the heating system. Systems are either designed to use either Hot Water or Steam as a medium, and components are usually specific to one or the other.
Hot Water
Heat Exchanger Material
Copper/Stainless
Fuel Type
Fuel Type
To create heat, some form of fuel is required. Fuel Type specifies what the product uses as an input to create heat.
Natural Gas
Combustion Type
Combustion Type
Condensing appliances use leftover thermal energy from combustion gases to heat water in a secondary heat exchanger, resulting in higher efficiency and lower exhaust temperature.
Condensing
Vent Type
Vent Type
Products that use combustion (burning) of fuel to create heat also create potentially dangerous gasses that need to be exhausted (AKA "Vented"). Depending on the product, venting can be done via a chimney, through a side wall, or use a second vent to provide fresh air to the appliance.
Outdoor (No Venting)
Storage Type
Tankless
Application
Residential
Mount Type
Wall
Installation Location
Outdoor
Maximum Altitude
6000 Feet
Includes Pump
No
Gas Conversion Kit
Not Available
Performance
Maximum Input Capacity
Maximum Input Capacity
The Maximum Input Capacity describes how quickly the appliance will use fuel when delivering it's maximum capacity. The units may change depending on the fuel being used.
199000 BTU
Minimum Input Capacity
15000 BTU
Flow Rate at 40F Temperature Rise
Flow Rate at 40F Temperature Rise
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location. Learn More
9.5 GPM
Flow Rate at 50F Temperature Rise
Flow Rate at 50F Temperature Rise
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location. Learn More
7.5 GPM
Flow Rate at 60F Temperature Rise
Flow Rate at 60F Temperature Rise
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location. Learn More
6.2 GPM
Flow Rate at 70F Temperature Rise
Flow Rate at 70F Temperature Rise
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location. Learn More
5.2 GPM
Uniform Energy Factor
Uniform Energy Factor
Uniform Energy Factor (UEF) is a measurement of water heater energy efficiency. The higher the energy factor, the more efficient the water heater.
0.95
Flow Rate at 77F Temperature Rise
4.8 GPM
Ultra Low NOx Emissions
Ultra Low NOx Emissions
NOx is a byproduct of the combustion process, and it's output is regulated in some jurisdictions. Many regulators mirror SCAQMD rules, which regulate air quality for some parts of Southern California. Ultra Low NOx appliances emit less than 10-14 ng/J (nanogram per Joule) of NOx. Learn More
Yes
Electrical Data
Voltage
120 Volts
Phase
1
Frequency
60 Hz
Dimensions
Gas Connection Size
3/4 Inch
Cold Water Inlet
3/4 Inch
Hot Water Outlet
3/4 Inch
Product Height
23 5/8 Inches
Product Width
17 3/4 Inches
Product Depth
11 1/4 Inches
Product Weight
59 Pounds
Shipping Weight
73 Pounds
Certifications
Energy Star Listed
Yes
CSA Listed
Yes
AHRI Certified
Yes
ANSI Certified
Yes
UPC Listed
No
AHRI Reference Number
207209455
Warranty Information
Parts Warranty
Parts Warranty
A warranty is a safeguard from defects in manufacturing and can vary in length and terms. Some manufacturers require registration for extended warranty benefits, be sure to check out features and the warranty document. To see the manufacturer's warranty statement, click on the Manuals tab. Learn More
5 Years
Heat Exchanger Warranty
15 Years
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A.O. Smith X3 - Residential 199,000 BTU - Natural Gas Tankless Water Heater - Outdoor
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