190,000 BTU tankless gas water heater for homes with up to three bathrooms.
The ATO-310U is A. O. Smith's most popular and versatile tankless model. It features a maximum flow rate of 8 GPM, providing enough hot water for three showers in warm climates, or up to two showers in colder climates at the same time.
New, Improved Features
• Heat-resistant copper heat exchanger tubing
• A remote control is included (item number 100209924). Install up to 400 feet from the heater using minimum 20 gauge control wire (not included).
• Thicker heat exchanger drum
• Includes a pump control port
• Easy-Link System for up to 4 units
• Set up for natural gas from factory, but field convertible from NG to LP with included gas conversion kit
• 190,000 BTUs
• Maximum flow rate of 8 GPM
• Non-condensing technology
• Ultra-Low NOx emissions (natural gas only). Complies with SCAQMD Rule 1146.2 for NOx emissions requirement of 14 ng/J or 20 ppm
• Complies with lead-free standards
• Built-in freeze protection
• Indoor models include factory-installed 120V power cord with plug
• Manual reset high limit (Set at 194°F)
• Overheat cutoff fuse
• Inlet and outlet thermistors for constant temperature monitoring
• Can be used for radiant/hydronic/space heating as well as the usual running hot water (domestic hot water/DHW). See page 36 of the installation manual (download below).
• Recess Box (for outdoor models)
• Pipe Cover
• Isolation Valve Kit