A. O. Smith Tankless Water Heater ATI-310CX3
- 8 GPM, 190000 BTU natural gas
- Field convertible to propane, kit included
- 0.81 UEF, non-condensing, copper heat exchanger
- 194°F maximum temperature, 150 psi maximum pressure
- For 2-3 bath homes, wall mount, indoor
- 15-year limited heat exchanger warranty
Updated 23 days ago · Based on the Amazon listing and published specifications, not hands-on testing.
A wall-mounted indoor tankless heater for a mid-size home, with scale prevention and a propane conversion kit in the box. It is non-condensing, and the maker recommends professional installation.
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ASIN: B0D1RK88FVModel: ATI-310CX3
Overview
A. O. Smith builds the ATI-310CX3 as an indoor natural gas tankless heater with a copper heat exchanger and a concentric vent system. A wall-mount body saves floor space, and integrated temperature controls and diagnostics handle operation.
X3 scale prevention and a propane kit in the box are the practical reasons to choose it, since descaling chores are cut and the fuel can change later. Venting and gas line work fall to an installer, and the rating suits mid-size homes rather than large ones.
Who it's for
Homeowners with two or three bathrooms and a natural gas line get a wall-mounted unit that can switch to propane later. Large households and DIY installers should note the size rating and the maker's installation advice.
Pros and cons
- Propane conversion kit included
- X3 scale prevention technology
- Copper heat exchanger
- Overheat cut-off fuse and air-fuel sensor
- Professional installation recommended
- Rated for mid-size homes only
Performance notes
Heat moves through a copper heat exchanger, and scale prevention aims to hold output steady over time, so the description says no annual descaling is required. Safety controls include exhaust and water temperature monitoring, an overheat cut-off fuse and an air-fuel ratio sensor. Flow rate decides how many fixtures can run together.
Specifications
| Brand | A. O. Smith |
|---|---|
| Model | ATI-310CX3 |
| Dimensions & fit | |
| Item Dimensions W X H | 13.75"W x 20.5"H |
| Item Weight | 51 pounds |
| Capacity & performance | |
| Flow Rate | 8 gpm |
| Heat Output | 190000 british thermal units |
| Maximum Temperature | 194 °F |
| Power & efficiency | |
| Efficiency | 0.81 UEF |
| Power Source | Natural Gas |
| Voltage | 120 volts |
| Construction & materials | |
| Color | White |
| Material Type | Copper |
| Compatibility & installation | |
| Mount Type | Wall |
| Included components | |
| Included Components | Tankless Water Heater, Propane Conversion Kit |
| Unit Count | 1 Count |
| Warranty & support | |
| Manufacturer Warranty Description | 15-Year Limited Warranty |
| Other details | |
| Item Highlight | For 2-3 Bath Homes |
| Item Type Name | water-heaters |
| Manufacture Year | 2025 |
| Maximum Pressure | 150 psi |
Frequently asked questions
Does the A. O. Smith ATI-310CX3 need descaling?
The description says X3 Scale Prevention Technology means no annual descaling or isolation valves are required.
Can I install the ATI-310CX3 myself?
The maker recommends professional installation. The unit uses a concentric vent system with vertical or horizontal termination.
Is the ATI-310CX3 a condensing heater?
No. It is listed as non-condensing, with a concentric vent system.