--- product_id: 650996156 title: "A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology" brand: "ao smith" price: "$4874.62" currency: USD in_stock: true url: https://www.desertcart.us/products/650996156-a-o-smith-tankless-water-heater-199-000-btu-proline store_origin: US region: United States of America --- # 199,000 BTU power 0.93 UEF ultra-efficiency X3 Scale Prevention Tech A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology **Brand:** ao smith **Price:** $4874.62 **Availability:** ✅ In Stock ## Summary > 🔥 Elevate your water heating game with pro-grade power and efficiency! ## Quick Answers - **What is this?** A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology by ao smith - **How much does it cost?** $4874.62 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/650996156-a-o-smith-tankless-water-heater-199-000-btu-proline) ## Best For - ao smith enthusiasts ## Why This Product - Trusted ao smith brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Built to Last:** 316L stainless steel secondary exchanger guards against corrosion for unmatched durability. - • **Rapid Heat Transfer:** Commercial-grade copper exchanger heats water faster and steadier than stainless steel rivals. - • **Smart Recirculation Ready:** Compatible with recirculation pump for instant hot water—comfort meets convenience. - • **Eco-Friendly Ultra-Low NOx:** Stay green and compliant with ultra-low emissions that protect your environment and reputation. - • **Consistent Peak Performance:** X3 Technology keeps efficiency razor-sharp over years—no slowdowns, no compromises. ## Overview The A. O. Smith ProLine® XE Indoor Tankless Water Heater delivers 199,000 BTU of natural gas power with cutting-edge X3 Scale Prevention Technology, ensuring sustained 0.93 UEF efficiency and ultra-low NOx emissions. Featuring a commercial-grade copper heat exchanger and corrosion-resistant stainless steel secondary exchanger, it guarantees rapid, reliable hot water flow up to 10 GPM, designed for long-lasting, eco-conscious indoor use. ## Description A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology ## Features - Maintains like-new performance for the life of the product vs. tankless models without X3 that show 10% efficiency reduction in the first 1.5 years - Primary commercial-grade copper heat exchanger is 25x better than stainless steel at heat transfer, stabilizing outgoing water temperatures quicker - Secondary heat exchanger is made of 316L Stainless Steel to protect against corrosion - Highly efficient condensing Ultra-Low Nox tankless water heater delivers up to .93 Uniform Energy Factor (UEF) - Recirculation pump capable with the use of a cross-over valve. Sold separately. ## Technical Specifications | Specification | Value | |---------------|-------| | Brand | AO Smith | | Product Dimensions | 17.75"W x 23.63"H | | Special Feature | X3 Scale Prevention Technology, Digital Display, Ultra-Low NOx Emissions, Highly Efficient (UEF 0.93) | | Wattage | 232.8 watts | | Voltage | 120 Volts | | Maximum Flow Rate | 10 Gallons Per Minute | | Efficiency | 0.93 | | Is Electric | No | | Manufacturer | A. O. Smith | | Item Depth | 11.25 | | UPC | 671657270148 | | Manufacture Year | 2023 | | Part Number | ATI-540HX3-N | | Item Weight | 72.9 pounds | | Country of Origin | USA | | Item model number | ATI-540HX3-N | | Installation Method | Indoor | | Item Package Quantity | 1 | | Special Features | X3 Scale Prevention Technology, Digital Display, Ultra-Low NOx Emissions, Highly Efficient (UEF 0.93) | | Included Components | Product Only | | Batteries Required? | No | ## Product Details - **Brand:** AO Smith - **Product Dimensions:** 17.75"W x 23.63"H - **Special Feature:** X3 Scale Prevention Technology, Digital Display, Ultra-Low NOx Emissions, Highly Efficient (UEF 0.93) - **Wattage:** 232.8 watts - **Voltage:** 120 Volts ## Images ![A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology - Image 1](https://m.media-amazon.com/images/I/61NPOIg1kOL.jpg) ![A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology - Image 2](https://m.media-amazon.com/images/I/71jLdenZaQL.jpg) ![A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology - Image 3](https://m.media-amazon.com/images/I/615NviEanSL.jpg) ![A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology - Image 4](https://m.media-amazon.com/images/I/71krSOGuA9L.jpg) ## Frequently Bought Together - A. O. Smith Tankless Water Heater 199,000 BTU ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology - SEAFLO 33-Series Industrial Water Pressure Pump w/Power Plug for Wall Outlet - 115VAC, 3.3 GPM, 45 PSI - Waterdrop AP431 AP430SS Whole House Scale Inhibitor Filter, Heater Softener System, Prevent Scale Build Up On Hot Water Heaters, Pipes and Boilers --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/650996156-a-o-smith-tankless-water-heater-199-000-btu-proline](https://www.desertcart.us/products/650996156-a-o-smith-tankless-water-heater-199-000-btu-proline) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-05-16*