Ao Smith 100384264 Condensing Tankless Water Heater

Product Description

The AO SMITH 100384264 is a standard condensing tankless water heater designed for residential natural gas applications. Running on up to 199,000 BTU/h of natural gas input, it delivers on-demand hot water with a maximum flow rate of 10.5 GPM. The unit features built-in X3 Scale Prevention Technology, which protects the heat exchanger from mineral buildup and can extend heat exchanger service life by up to 300 percent compared to an unprotected unit. A built-in control display allows technicians to set operating parameters and read error codes directly from the unit. This model carries ENERGY STAR certification with a Uniform Energy Factor of 0.95 and complies with Ultra-Low NOx emissions regulations.

This unit is rated for residential installation and can be mounted indoors or outdoors. An outdoor vent cap kit is required for outdoor installation and is sold separately. For larger commercial-adjacent or multi-unit residential projects requiring higher hot water demand, up to 12 units of the same model can be cascaded together using the included cable. This flexibility makes the heater a practical choice for high-demand residential settings where a single unit may not cover peak load requirements. Licensed plumbers and HVAC technicians are the typical installing trade for this type of condensing tankless appliance.

Key Features

• 199,000 BTU/h natural gas input with a maximum flow rate of 10.5 GPM
• Built-in X3 Scale Prevention Technology protects the heat exchanger from mineral buildup
• ENERGY STAR certified with a Uniform Energy Factor of 0.95
• Complies with Ultra-Low NOx emissions regulations
• Built-in control display for status monitoring and error code reading
• Cascade capability for up to 12 units using the included cable
• Rated for both indoor and outdoor installation

Compatibility

This unit corresponds to model number ATM-199X3-N within the Adapt SC product line. Outdoor installation requires a separately purchased vent cap kit. Designed as an OEM-style replacement or direct installation unit for residential condensing natural gas tankless water heater applications.

Installation Notes

Installation must be performed by a licensed plumber or qualified HVAC technician in accordance with local plumbing codes and the manufacturer instructions. Shut off the gas supply and cold water inlet before beginning any service or installation work. The unit operates on 120 volts and requires a properly grounded electrical connection per NEC requirements. Do not attempt to modify gas valve settings, venting configuration, or cascade wiring beyond what is specified in the installation documentation.

Technical Specifications

• Input Capacity: 199,000 BTU/h
• Maximum Flow Rate: 10.5 GPM
• Fuel Source: Natural Gas
• Voltage: 120 volts
• Uniform Energy Factor: 0.95
• Application Class: Residential
• Width: 17.4 inches
• Length: 39.25 inches
• Height: 22.1 inches
• Emissions Compliance: Ultra-Low NOx

Standard Information

• Brand: AO SMITH
• Manufacturer Part Number: 100384264