A. O. Smith ATM-199X3-N ADAPT® SC Standard Condensing Tankless Water Heater is engineered to provide reliable, high-efficiency hot water with minimal maintenance requirements. Designed for residential applications that demand consistent performance, this condensing tankless water heater features patented X3™ Scale Prevention Technology, helping the system maintain like-new performance longer while eliminating the need for annual descaling.
With an impressive 199,000 BTU/h heating capacity, 0.95 UEF efficiency, and ENERGY STAR® certification, ATM-199X3-N delivers powerful hot water performance while helping homeowners reduce energy consumption. Whether you have a large household or multiple simultaneous hot water demands, this system provides dependable, on-demand comfort.
ATM-199X3-N also offers flexible installation options with support for PVC, CPVC, or polypropylene venting, built-in freeze protection, and the ability to cascade up to 12 units, making it a highly versatile solution for residential hot water needs.
Patented X3™ Scale Prevention Technology
One of the standout features of ATM-199X3-N is its integrated X3™ Scale Prevention Technology. This patented design helps reduce mineral scale buildup, extends the lifespan of the unit by up to three times compared to unprotected systems, and removes the need for annual descaling maintenance.
High-Efficiency Condensing Operation
ATM-199X3-N is designed to maximize energy savings with a 0.95 Uniform Energy Factor (UEF). As an ENERGY STAR® certified tankless water heater, it helps lower monthly utility costs while delivering dependable hot water when you need it.
Powerful 199,000 BTU Heating Capacity
With up to 199,000 BTU/h input, this tankless water heater is ideal for larger homes and high-demand households. The system provides a maximum flow rate of 10.5 GPM, allowing multiple showers, sinks, dishwashers, and laundry appliances to run simultaneously.
Flexible Venting Options
Installation flexibility is a major advantage of ATM-199X3-N. The system supports ULC S636 certified PVC, CPVC, and polypropylene venting materials, with venting lengths of up to 150 feet using 3-inch PVC.
Commercial-Grade Durability
Built for long-term reliability, ATM-199X3-N features a primary copper heat exchanger combined with a secondary stainless steel heat exchanger, providing superior durability and heat transfer efficiency.
Freeze Protection for Cold Weather Reliability
Built-in freeze protection safeguards the unit in temperatures as low as -5°F (-21°C), offering additional peace of mind in colder climates.
| Brand | A. O. Smith |
|---|---|
| Model | ATM-199X3-N |
| Series | ADAPT® SC Standard Condensing Tankless |
| Installation Type | Indoor |
| Fuel Type | Natural Gas |
| Maximum Input | 199,000 BTU/h |
| Minimum Input | 10,000 BTU/h |
| Maximum Flow Rate | 10.5 GPM |
| Activation Flow Rate | 0.4 GPM |
| Continuous Fire Flow Rate | 0.26 GPM |
| Uniform Energy Factor (UEF) | 0.95 |
| Certification | ENERGY STAR® Certified |
| Emissions | Ultra Low NOx |
| Temperature Range | 100°F – 140°F |
| Default Temperature Setting | 120°F |
| Water Pressure Range | 15 – 150 PSI |
| Recommended Water Pressure | 40 PSI |
| Water Connections | 3/4" NPT |
| Gas Connection | 3/4" NPT |
| Ignition System | Electronic Ignition |
| Power Supply | 120V, 50/60Hz, <5A |
| Height | 40.4" |
| Width | 17.1" |
| Depth | 11.9" |
| Weight | 83 lbs |
| Sound Level | 51 dB |
| Freeze Protection | Down to -5°F (-21°C) |
| Cascade Capability | Up to 12 Units |
| Included Components | Pressure Relief Valve, Wall Mounting Bracket, Hardware, Vent Port Screws, Cascading Cable, Bird Screens |
A. O. Smith ATM-199X3-N stands out for homeowners looking for a high-performance, low-maintenance tankless water heater. Unlike traditional tankless systems that often require yearly descaling, the patented X3™ technology helps prevent scale buildup and reduces ongoing maintenance costs.
Its combination of high heating capacity, ENERGY STAR® efficiency, flexible venting, and commercial-grade heat exchanger design makes it an excellent choice for larger households, luxury homes, and demanding residential hot water applications.
Pacific Blue Mechanical provides professional supply, installation, repair, maintenance, and replacement services for the A. O. Smith ATM-199X3-N ADAPT® SC Standard Condensing Tankless Water Heater throughout Metro Vancouver and surrounding areas.
If requested, we can source and supply this high-efficiency A. O. Smith tankless water heater directly and carry out a complete professional installation process, including natural gas line connection, cold and hot water piping integration, venting system installation, condensate drainage setup, wall mounting, system startup, and full commissioning to ensure safe and optimal performance.
Our licensed technicians also provide ongoing tankless water heater maintenance and repair services, including X3™ scale prevention system checks, heat exchanger inspection, flow sensor diagnostics, ignition troubleshooting, water pressure balancing, error code analysis, venting performance checks, and complete system flushing and replacement services when required.
If your current tankless water heater is experiencing inconsistent hot water, reduced efficiency, ignition issues, flow problems, or is approaching the end of its service life, our team can evaluate your system and recommend the most cost-effective repair or full replacement solution tailored to your home’s hot water demand.
Looking to upgrade to A. O. Smith ATM-199X3-N tankless water heater? Pacific Blue Mechanical provides professional tankless water heater installation, replacement, and repair services. Contact our experienced team today to find the right hot water solution for your home.
X3™ Scale Prevention Technology is A. O. Smith’s patented system designed to reduce scale buildup inside the water heater, helping maintain efficiency and eliminate the need for annual descaling.
The unit can provide up to 10.5 gallons per minute (GPM), allowing multiple fixtures and appliances to operate simultaneously.
Yes. The ATM-199X3-N is ENERGY STAR® certified and offers a 0.95 UEF rating, helping improve energy efficiency and lower operating costs.
No. Thanks to its integrated X3™ Scale Prevention Technology, this model is designed to eliminate the need for annual descaling under standard operating conditions.
The unit includes a 15-year limited residential warranty on the heat exchanger, a 5-year parts warranty for residential applications, and a 1-year limited warranty for commercial applications.
