ProLine® XE Ultra-Low NOx Outdoor 190,000 BTU Non-Condensing Natural Gas/Liquid Propane Tankless Water Heater

Model ATO-310U
5 out of 5 Customer Rating
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Installation Type
Maximum BTU's
  • Continuous flow rate up to 8.0 GPM
  • Wall-mount design saves valuable space and allows for additional storage and flexibility
  • Commercial-grade copper heat exchanger is 25x better than stainless steel at heat transfer, stabilizing outgoing water temperatures quicker
Product Details
  • Continuous flow rate up to 8.0 GPM
  • Wall-mount design saves valuable space and allows for additional storage and flexibility
  • Commercial-grade copper heat exchanger is 25x better than stainless steel at heat transfer, stabilizing outgoing water temperatures quicker
  • Easily convertible from natural gas to propane with supplied kit
  • Highly efficient condensing Ultra-Low Nox tankless water heater delivers up to .81 Uniform Energy Factor (UEF)
  • Vents up to 60 feet using 4” Category III Stainless Steel
  • Includes integrated temperature controls and advanced diagnostics to simplify troubleshooting
  • Safety features include built-in freeze protection, overheat cut-off fuse and air-fuel ratio (AFR) sensor
  • 15-year limited warranty on heat exchanger in residential applications

  • The 310U Series is great for two bath homes in cold climates. The 310U features a max flow rate of 8.0 gallons per minute providing enough hot water to run three showers at the same time. The design allows for a variety of installation options. Complies with Ultra-Low NOx regulations and meets energy efficiency requirements of ASHRAE 90.1b-1992. The ATO-310U tankless water heater uses up to 190,000 BTU/h of natural gas/liquid propane to deliver an endless supply of hot water for a 2.5 bath home in northern climates and up to a 3.5 bath home in southern climates (one shower head per bath). The ATO-310U has a Uniform Energy Factor of 0.81. With an industry leading 15-year limited warranty, the ATO-310U tankless water heater provides years of hot water through innovation and quality. A. O. Smith’s ProLine® water heaters are residential products built to commercial-grade standard and are only available for purchase through professional wholesalers and contractors.

Specifications
Tech Specs
UEF
0.82
Maximum BTUs
190,000
Power Source
GAS
Limited Parts Warranty
5 Years
Water Connection Location
BOTTOM
Emissions
Ultra-Low NOx
ASME Certified
No
Destination Country
US
Digital Display
true
Fuel Source
NATURAL
Installation Type
OUTDOOR
Limited Heat Exchanger Warranty 
15 Years
Max Flow Rate
4.80
Minimum BTUs
15,000.00
Application
RESIDENTIAL
Product Tier
ProLine® XE
Shipping Height 
28
Shipping Length 
16.625
Shipping Width 
12.375
Side Loop
No
Dimension & Venting
Type
Water Heater
Height
20.5"
Width
13.75"
Shipping Weight
39lbs
Vent Type
Direct Vent
Find a Replacement
Current Product
Option 2
Option 3
ProLine® XE Ultra-Low NOx Outdoor 190,000 BTU Non-Condensing Natural Gas/Liquid Propane Tankless Water Heater
ProLine® XE Ultra-Low NOx Outdoor 199,000 BTU Non-Condensing Natural Gas/Liquid Propane Tankless Water Heater
ProLine® XE Ultra-Low NOx Outdoor 160,000 BTU Condensing Propane Tankless Water Heater
ATO-310U
ATO-510U
ATO-240H
Rebates up to $300 +
Rebates up to $300 +
Rebates up to $300 +
Width
13.75"
13.75"
17.75"
Depth
9.5"
9.5"
11.25"
Height
20.5"
20.5"
23.63"
Shipping Weight
39lbs
40lbs
69lbs
Power Source
GAS
GAS
GAS
Limited Tank Warranty
0 Years
0 Years
0 Years
Limited Parts Warranty
5 Years
5 Years
5 Years
Water Connection Location
BOTTOM
BOTTOM
BOTTOM
Water Connection Size
0.75"
Thermal Efficiency
0%
0%
0%
All Reviews for ProLine® XE Tankless Non-Condensing Ultra-Low Nox (200 series)
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