{"product_id":"a-o-smith-signature-300-40-gallon-tall-12-year-limited-40000-btu-natural-gas-water-heater","title":"A.O. Smith Signature 300 40-Gallon Tall 40000-BTU Natural Gas Water Heater - Item #839885 | Model #G12-CADT4040NV","description":"\u003ch2 class=\"romance\"\u003eA.O. Smith Signature 300 40-Gallon Tall 40000-BTU Natural Gas Water Heater - Item #839885 | Model #G12-CADT4040NV\u003c\/h2\u003e\n\u003cdiv class=\"romance\"\u003eA. O. Smith's Signature 300 Series 40-gallon gas water heater provides reliable hot water for households with 3 to 4 people when sized appropriately. With an environmentally friendly 40,000 Btu\/h Low-NOx gas burner, this flue damper model delivers 80 gallons of hot water in the first hour. This water heater does not require external power and is as simple as a standard atmospheric model. The automatic damper prevents cool air from traveling through the flue in standby mode to maintain overall heat and efficiency. The natural gas hot water heater is built with safety in mind. It has a safety system that reduces the risk of accidental flammable vapor ignitions. A factory-installed temperature and pressure relief valve and tamper-proof drain valve also ensure safe operation. This model is built to last. It features Tank Guard® which is designed to provide ultimate tank protection and increase lifespan of the water heater. This added protection comes with a  for additional peace of mind.\u003c\/div\u003e\n\u003ch5 class=\"romance\"\u003eFeatures\u003c\/h5\u003e\n\u003cdiv class=\"specs\"\u003e\n\u003cul class=\"bullets\"\u003e\n\u003cli\u003e\n\u003cp\u003eDelivers the ideal amount of hot water for households with 3 to 4 people when sized appropriately\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFitted with an automatic flue damper that opens and closes automatically to increase efficiency and reduce heat loss in standby mode\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSimple installation that uses standard 3-in or 4-in vent ducting and requires no power\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFeatures an environmentally friendly 40,000 BTU low NOx gas burner that delivers 82 gallons in the first hour\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTank Guardprovides advanced tank protection that extends the life of your gas water heater\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eTall, slim 62.5-in high x 20-in diameter profile enables easier installation in narrow spaces\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHigh-altitude certified from 0 ft to 10,100 ft\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003eSpecifications\u003c\/h5\u003e\n\u003c\/div\u003e\n\u003cstyle type=\"text\/css\"\u003e\n.tg  {border-collapse:collapse;border-spacing:0;}\n.tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\n  overflow:hidden;padding:10px 5px;word-break:normal;}\n.tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\n  font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;}\n.tg .tg-cly1{text-align:left;vertical-align:middle}\n.tg .tg-w22m{background-color:#ffffff;border-color:#000000;color:#000000;font-weight:bold;text-align:left;vertical-align:middle}\n.tg .tg-8c31{background-color:#ffffff;border-color:#000000;color:#000000;text-align:left;vertical-align:middle}\n.tg .tg-yla0{font-weight:bold;text-align:left;vertical-align:middle}\n\u003c\/style\u003e\n\u003cdiv class=\"specs\"\u003e\n\u003ctable class=\"tg\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth class=\"tg-w22m\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eDiameter (Inches)    \u003c\/th\u003e\n\u003cth class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e20.0    \u003c\/th\u003e\n\u003cth class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eRated Storage Capacity    \u003c\/th\u003e\n\u003cth class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e38-Gallon    \u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"tg-w22m\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eFamily Size    \u003c\/td\u003e\n\u003ctd class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e4.0    \u003c\/td\u003e\n\u003ctd class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eVent Diameter(s)    \u003c\/td\u003e\n\u003ctd class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e3-in; 4-in    \u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"tg-w22m\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eHeight (Inches)    \u003c\/td\u003e\n\u003ctd class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e62.5    \u003c\/td\u003e\n\u003ctd class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eWater Connection Size    \u003c\/td\u003e\n\u003ctd class=\"tg-8c31\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e3\/4-in    \u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"tg-yla0\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eInsulation Thickness (Inches)    \u003c\/td\u003e\n\u003ctd class=\"tg-cly1\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e2.0    \u003c\/td\u003e\n\u003ctd class=\"tg-cly1\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eWeight (lbs.)    \u003c\/td\u003e\n\u003ctd class=\"tg-cly1\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e135.0    \u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"tg-yla0\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eNominal Capacity (Gallons)    \u003c\/td\u003e\n\u003ctd class=\"tg-cly1\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e40    \u003c\/td\u003e\n\u003ctd class=\"tg-cly1\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e   \u003c\/td\u003e\n\u003ctd class=\"tg-cly1\"\u003e\n\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e    \u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch5\u003eWhat our Experts Think\u003c\/h5\u003e\n\u003cul data-start=\"27\" data-end=\"1623\"\u003e\n\u003cli data-section-id=\"1kdbmx\" data-start=\"27\" data-end=\"322\"\u003e\n\u003cp data-start=\"29\" data-end=\"322\"\u003e\u003cstrong data-start=\"29\" data-end=\"61\"\u003eStrong everyday performance:\u003c\/strong\u003e This \u003cstrong data-start=\"67\" data-end=\"110\"\u003e40‑gallon tall natural gas water heater\u003c\/strong\u003e delivers a \u003cstrong data-start=\"122\" data-end=\"171\"\u003erobust first‑hour hot water output (~80+ gal)\u003c\/strong\u003e with a \u003cstrong data-start=\"179\" data-end=\"208\" data-is-only-node=\"\"\u003e40,000 BTU Low‑NOx burner\u003c\/strong\u003e, ideal for \u003cstrong data-start=\"220\" data-end=\"246\"\u003ehomes with ~3–4 people\u003c\/strong\u003e doing showers, laundry, and dishes. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"14m2ssn\" data-start=\"323\" data-end=\"557\"\u003e\n\u003cp data-start=\"325\" data-end=\"557\"\u003e\u003cstrong data-start=\"325\" data-end=\"362\"\u003eENERGY STAR‑certified efficiency:\u003c\/strong\u003e The \u003cstrong data-start=\"367\" data-end=\"392\"\u003eautomatic flue damper\u003c\/strong\u003e increases efficiency by reducing standby heat loss, helping lower annual energy costs compared with basic atmospheric units. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"ycmrqt\" data-start=\"558\" data-end=\"801\"\u003e\n\u003cp data-start=\"560\" data-end=\"801\"\u003e\u003cstrong data-start=\"560\" data-end=\"588\"\u003eDurable tank protection:\u003c\/strong\u003e \u003cstrong data-start=\"589\" data-end=\"634\"\u003eTank Guard® and fused ceramic tank shield\u003c\/strong\u003e help resist corrosion and extend service life, backed by a \u003cstrong data-start=\"694\" data-end=\"734\"\u003e12‑year limited residential warranty\u003c\/strong\u003e for lasting peace of mind. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1ilg8lk\" data-start=\"802\" data-end=\"1031\"\u003e\n\u003cp data-start=\"804\" data-end=\"1031\"\u003e\u003cstrong data-start=\"804\" data-end=\"842\"\u003ePrecise temperature \u0026amp; diagnostics:\u003c\/strong\u003e \u003cstrong data-start=\"843\" data-end=\"895\"\u003eElectronic gas control with LED status indicator\u003c\/strong\u003e provides accurate temperature regulation and self‑diagnostics that make troubleshooting easier. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1eop2we\" data-start=\"1032\" data-end=\"1237\"\u003e\n\u003cp data-start=\"1034\" data-end=\"1237\"\u003e\u003cstrong data-start=\"1034\" data-end=\"1065\"\u003eSpace‑friendly tall design:\u003c\/strong\u003e Slim tall profile fits better in closets and utility rooms with limited floor space while still offering full residential capacity. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"u7z3kc\" data-start=\"1238\" data-end=\"1425\"\u003e\n\u003cp data-start=\"1240\" data-end=\"1425\"\u003e\u003cstrong data-start=\"1240\" data-end=\"1266\"\u003eHigh‑altitude capable:\u003c\/strong\u003e Certified for installation from \u003cstrong data-start=\"1299\" data-end=\"1331\"\u003e0 ft to ~10,100 ft elevation\u003c\/strong\u003e, making it versatile for varied geographic locations. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"jbuc23\" data-start=\"1426\" data-end=\"1623\"\u003e\n\u003cp data-start=\"1428\" data-end=\"1623\"\u003e\u003cstrong data-start=\"1428\" data-end=\"1448\"\u003eSafety built in:\u003c\/strong\u003e Factory‑installed \u003cstrong data-start=\"1467\" data-end=\"1506\"\u003etemperature \u0026amp; pressure relief valve\u003c\/strong\u003e and \u003cstrong data-start=\"1511\" data-end=\"1539\"\u003etamper‑proof drain valve\u003c\/strong\u003e support reliable, code‑compliant operation. \u003cspan class=\"\" data-state=\"delayed-open\" aria-describedby=\"radix-_r_5i_\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1625\" data-end=\"1894\"\u003e \u003c\/p\u003e\n\u003ch5\u003e\n\u003cbr\u003eQ\u0026amp;A\u003c\/h5\u003e\n\u003cp data-start=\"106\" data-end=\"281\"\u003e\u003cstrong data-start=\"106\" data-end=\"163\"\u003eQ: What household size is this water heater best for?\u003c\/strong\u003e\u003cbr data-start=\"163\" data-end=\"166\"\u003eA: Ideal for \u003cstrong data-start=\"179\" data-end=\"207\"\u003ehouseholds of 2–3 people\u003c\/strong\u003e, providing consistent hot water for showers, laundry, and everyday use.\u003c\/p\u003e\n\u003cp data-start=\"283\" data-end=\"418\"\u003e\u003cstrong data-start=\"283\" data-end=\"320\"\u003eQ: What type of fuel does it use?\u003c\/strong\u003e\u003cbr data-start=\"320\" data-end=\"323\"\u003eA: Operates on \u003cstrong data-start=\"338\" data-end=\"353\"\u003enatural gas\u003c\/strong\u003e, delivering reliable heating and energy-efficient performance.\u003c\/p\u003e\n\u003cp data-start=\"420\" data-end=\"545\"\u003e\u003cstrong data-start=\"420\" data-end=\"454\"\u003eQ: How powerful is the heater?\u003c\/strong\u003e\u003cbr data-start=\"454\" data-end=\"457\"\u003eA: Features a \u003cstrong data-start=\"471\" data-end=\"492\"\u003e40,000-BTU burner\u003c\/strong\u003e for fast recovery and consistent hot water supply.\u003c\/p\u003e\n\u003cp data-start=\"547\" data-end=\"694\"\u003e\u003cstrong data-start=\"547\" data-end=\"604\"\u003eQ: What are the dimensions of this tall water heater?\u003c\/strong\u003e\u003cbr data-start=\"604\" data-end=\"607\"\u003eA: Designed as a \u003cstrong data-start=\"624\" data-end=\"648\"\u003etall, narrow profile\u003c\/strong\u003e, ideal for closets or small utility spaces.\u003c\/p\u003e\n\u003cp data-start=\"696\" data-end=\"862\"\u003e\u003cstrong data-start=\"696\" data-end=\"735\"\u003eQ: Does it include safety features?\u003c\/strong\u003e\u003cbr data-start=\"735\" data-end=\"738\"\u003eA: Yes. Includes a \u003cstrong data-start=\"757\" data-end=\"798\"\u003etemperature and pressure relief valve\u003c\/strong\u003e and other standard safety protections for reliable operation.\u003c\/p\u003e\n\u003cp data-start=\"864\" data-end=\"998\"\u003e\u003cstrong data-start=\"864\" data-end=\"894\"\u003eQ: Is it energy efficient?\u003c\/strong\u003e\u003cbr data-start=\"894\" data-end=\"897\"\u003eA: Yes. The Signature 300 Series is designed for \u003cstrong data-start=\"946\" data-end=\"973\"\u003ehigh thermal efficiency\u003c\/strong\u003e and reduced gas usage.\u003c\/p\u003e\n\u003cp data-start=\"1000\" data-end=\"1149\"\u003e\u003cstrong data-start=\"1000\" data-end=\"1033\"\u003eQ: How is the tank protected?\u003c\/strong\u003e\u003cbr data-start=\"1033\" data-end=\"1036\"\u003eA: Equipped with a \u003cstrong data-start=\"1055\" data-end=\"1079\"\u003eprotective anode rod\u003c\/strong\u003e and premium tank materials to resist corrosion and extend lifespan.\u003c\/p\u003e\n\u003cp data-start=\"1151\" data-end=\"1298\"\u003e\u003cstrong data-start=\"1151\" data-end=\"1197\"\u003eQ: What are the installation requirements?\u003c\/strong\u003e\u003cbr data-start=\"1197\" data-end=\"1200\"\u003eA: Requires \u003cstrong data-start=\"1212\" data-end=\"1238\"\u003enatural gas connection\u003c\/strong\u003e, proper venting, and \u003cstrong data-start=\"1260\" data-end=\"1295\"\u003eindoor residential installation\u003c\/strong\u003e.\u003c\/p\u003e\n\u003ch5\u003e\n\u003cbr\u003eMaintenance Tips\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli data-section-id=\"1a30npj\" data-start=\"128\" data-end=\"271\"\u003e\n\u003cp data-start=\"130\" data-end=\"271\"\u003e\u003cstrong data-start=\"130\" data-end=\"170\"\u003eInspect and flush the tank annually:\u003c\/strong\u003e Drain and flush the tank \u003cstrong data-start=\"196\" data-end=\"217\"\u003eevery 6–12 months\u003c\/strong\u003e to remove sediment and maintain heating efficiency.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"hm3jy\" data-start=\"272\" data-end=\"408\"\u003e\n\u003cp data-start=\"274\" data-end=\"408\"\u003e\u003cstrong data-start=\"274\" data-end=\"298\"\u003eCheck the anode rod:\u003c\/strong\u003e Inspect the \u003cstrong data-start=\"311\" data-end=\"343\"\u003esacrificial anode rod yearly\u003c\/strong\u003e and replace if heavily corroded to prevent internal tank rust.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1t3k1s1\" data-start=\"409\" data-end=\"545\"\u003e\n\u003cp data-start=\"411\" data-end=\"545\"\u003e\u003cstrong data-start=\"411\" data-end=\"448\"\u003eExamine gas and vent connections:\u003c\/strong\u003e Ensure \u003cstrong data-start=\"456\" data-end=\"492\"\u003egas lines, fittings, and venting\u003c\/strong\u003e are secure, unobstructed, and free from corrosion.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1rz7aa6\" data-start=\"546\" data-end=\"679\"\u003e\n\u003cp data-start=\"548\" data-end=\"679\"\u003e\u003cstrong data-start=\"548\" data-end=\"578\"\u003eTest the T\u0026amp;P relief valve:\u003c\/strong\u003e Operate the \u003cstrong data-start=\"591\" data-end=\"637\"\u003etemperature \u0026amp; pressure relief valve yearly\u003c\/strong\u003e to ensure it opens properly and safely.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1308fkv\" data-start=\"680\" data-end=\"812\"\u003e\n\u003cp data-start=\"682\" data-end=\"812\"\u003e\u003cstrong data-start=\"682\" data-end=\"711\"\u003eMonitor burner operation:\u003c\/strong\u003e Watch for \u003cstrong data-start=\"722\" data-end=\"767\"\u003eirregular ignition or flame color changes\u003c\/strong\u003e, which may indicate venting or gas issues.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"15k4rne\" data-start=\"813\" data-end=\"929\"\u003e\n\u003cp data-start=\"815\" data-end=\"929\"\u003e\u003cstrong data-start=\"815\" data-end=\"837\"\u003eInspect for leaks:\u003c\/strong\u003e Regularly check \u003cstrong data-start=\"854\" data-end=\"900\"\u003ewater connections, fittings, and tank base\u003c\/strong\u003e for moisture or corrosion.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"16bmp0c\" data-start=\"930\" data-end=\"1087\"\u003e\n\u003cp data-start=\"932\" data-end=\"1087\"\u003e\u003cstrong data-start=\"932\" data-end=\"970\"\u003eMaintain proper space and airflow:\u003c\/strong\u003e Keep the area around the water heater \u003cstrong data-start=\"1009\" data-end=\"1044\"\u003eclean, dry, and well-ventilated\u003c\/strong\u003e for safe operation and easy maintenance.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"A.O. Smith","offers":[{"title":"Default Title","offer_id":46812822044809,"sku":"Item #839885 | Model #G12-CADT4040NV","price":999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0759\/2443\/9177\/files\/image_988d8095-d0d7-4582-92fe-318204044cbe.png?v=1779806766","url":"https:\/\/mobility-ready.com\/products\/a-o-smith-signature-300-40-gallon-tall-12-year-limited-40000-btu-natural-gas-water-heater","provider":"Supplies for Happy Tails","version":"1.0","type":"link"}