{"product_id":"suburban-521099-ignition-control-circuit-board-12v-furnace-replacement-520741-520820","title":"Suburban 521099 Ignition Control Circuit Board – 12V Furnace Replacement (520741 \/ 520820)","description":"\u003ch2 data-section-id=\"53drpp\" data-start=\"226\" data-end=\"247\"\u003eProduct Overview\u003c\/h2\u003e\n\u003cp data-start=\"248\" data-end=\"578\"\u003eThe \u003cstrong data-start=\"252\" data-end=\"302\"\u003eSuburban 521099 Ignition Control Circuit Board\u003c\/strong\u003e is the upgraded, direct replacement for older Suburban furnace control boards, including \u003cstrong data-start=\"392\" data-end=\"413\"\u003e520741 and 520820\u003c\/strong\u003e. Designed for Suburban 12V RV furnaces, this board acts as the “brain” of your heating system—controlling ignition, monitoring flame, and managing blower operation.\u003c\/p\u003e\n\u003cp data-start=\"580\" data-end=\"812\"\u003eBuilt with integrated fan control (3rd generation \/ 3G design), this module improves furnace performance, safety, and reliability—making it one of the most commonly replaced and most important components in Suburban furnace systems.\u003c\/p\u003e\n\u003cp data-start=\"814\" data-end=\"902\"\u003eImportant: This board is \u003cstrong data-start=\"839\" data-end=\"858\"\u003e12 Volt DC ONLY\u003c\/strong\u003e and will \u003cstrong data-start=\"868\" data-end=\"901\"\u003eNOT replace 24 Volt AC boards\u003c\/strong\u003e.\u003c\/p\u003e\n\u003chr data-start=\"904\" data-end=\"907\"\u003e\n\u003ch2 data-section-id=\"14at72t\" data-start=\"909\" data-end=\"926\"\u003eKey Features\u003c\/h2\u003e\n\u003cul data-start=\"927\" data-end=\"1493\"\u003e\n\u003cli data-section-id=\"13l4fpl\" data-start=\"927\" data-end=\"985\"\u003eDirect replacement for Suburban 520741 \u0026amp; 520820 boards\u003c\/li\u003e\n\u003cli data-section-id=\"zyswh\" data-start=\"986\" data-end=\"1069\"\u003eWorks on all Suburban 12V furnaces (SF \u0026amp; NT series)\n\u003cul data-start=\"1044\" data-end=\"1069\"\u003e\n\u003cli data-section-id=\"1oue88n\" data-start=\"1044\" data-end=\"1069\"\u003eExcludes NT-45S model\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli data-section-id=\"1u8yi4h\" data-start=\"1070\" data-end=\"1131\"\u003e3rd Generation (3G) DSI board with integrated fan control\u003c\/li\u003e\n\u003cli data-section-id=\"1cgx9ey\" data-start=\"1132\" data-end=\"1201\"\u003eControls full ignition sequence (spark, gas valve, flame sensing)\u003c\/li\u003e\n\u003cli data-section-id=\"12geyyh\" data-start=\"1202\" data-end=\"1250\"\u003eBuilt-in safety lockout and flame monitoring\u003c\/li\u003e\n\u003cli data-section-id=\"hgwrtq\" data-start=\"1251\" data-end=\"1302\"\u003ePlug-and-play installation in most applications\u003c\/li\u003e\n\u003cli data-section-id=\"1l5muhh\" data-start=\"1303\" data-end=\"1404\"\u003eIf replacing a board without fan control, a separate wiring harness is required (sold separately)\u003c\/li\u003e\n\u003cli data-section-id=\"1cz8tce\" data-start=\"1405\" data-end=\"1445\"\u003e3-year manufacturer limited warranty\u003c\/li\u003e\n\u003cli data-section-id=\"1cfb1lt\" data-start=\"1446\" data-end=\"1493\"\u003eCompact, durable design for RV environments\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1495\" data-end=\"1498\"\u003e\n\u003ch2 data-section-id=\"1qhk4i3\" data-start=\"1500\" data-end=\"1519\"\u003eSpecifications\u003c\/h2\u003e\n\u003cul data-start=\"1520\" data-end=\"1751\"\u003e\n\u003cli data-section-id=\"1cger40\" data-start=\"1520\" data-end=\"1543\"\u003ePart Number: 521099\u003c\/li\u003e\n\u003cli data-section-id=\"xsy82d\" data-start=\"1544\" data-end=\"1567\"\u003eVoltage: 12 Volt DC\u003c\/li\u003e\n\u003cli data-section-id=\"1n16wbq\" data-start=\"1568\" data-end=\"1621\"\u003eFunction: Ignition control and blower fan control\u003c\/li\u003e\n\u003cli data-section-id=\"ddr6lm\" data-start=\"1622\" data-end=\"1676\"\u003eApplication: Suburban RV furnaces (SF \u0026amp; NT series)\u003c\/li\u003e\n\u003cli data-section-id=\"o1c0vs\" data-start=\"1677\" data-end=\"1699\"\u003eExclusions: NT-45S\u003c\/li\u003e\n\u003cli data-section-id=\"1l9ykk8\" data-start=\"1700\" data-end=\"1751\"\u003eNot Compatible With: 24 Volt AC furnace systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1753\" data-end=\"1756\"\u003e\n\u003ch2 data-section-id=\"2p3a71\" data-start=\"1758\" data-end=\"1784\"\u003eReplaces Part Numbers\u003c\/h2\u003e\n\u003cul data-start=\"1785\" data-end=\"1884\"\u003e\n\u003cli data-section-id=\"byxogd\" data-start=\"1785\" data-end=\"1795\"\u003e520741\u003c\/li\u003e\n\u003cli data-section-id=\"bwqbid\" data-start=\"1796\" data-end=\"1806\"\u003e520820\u003c\/li\u003e\n\u003cli data-section-id=\"bwo15t\" data-start=\"1807\" data-end=\"1817\"\u003e520871\u003c\/li\u003e\n\u003cli data-section-id=\"bwshpe\" data-start=\"1818\" data-end=\"1828\"\u003e520814\u003c\/li\u003e\n\u003cli data-section-id=\"x2utw4\" data-start=\"1829\" data-end=\"1839\"\u003e33550L\u003c\/li\u003e\n\u003cli data-section-id=\"3eypzz\" data-start=\"1840\" data-end=\"1884\"\u003eMultiple legacy Suburban ignition boards\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1886\" data-end=\"1889\"\u003e\n\u003ch2 data-section-id=\"yzynuf\" data-start=\"1891\" data-end=\"1921\"\u003eCompatible Furnace Models\u003c\/h2\u003e\n\u003ch3 data-section-id=\"dmdozq\" data-start=\"1923\" data-end=\"1947\"\u003eSuburban SF Series\u003c\/h3\u003e\n\u003cp data-start=\"1948\" data-end=\"2027\"\u003eSF-20 \/ SF-25 \/ SF-30 \/ SF-35 \/ SF-42\u003cbr data-start=\"1985\" data-end=\"1988\"\u003eSF-Q, SF-FQ, SF-VHQ, SF-VHFQ variants\u003c\/p\u003e\n\u003ch3 data-section-id=\"1mqc26h\" data-start=\"2029\" data-end=\"2053\"\u003eSuburban NT Series\u003c\/h3\u003e\n\u003cp data-start=\"2054\" data-end=\"2168\"\u003eNT-12 \/ NT-16 \/ NT-20 \/ NT-24 \/ NT-25 \/ NT-30 \/ NT-34 \/ NT-40 \/ NT-42\u003cbr data-start=\"2123\" data-end=\"2126\"\u003eNT-S, NT-SE, NT-SP, NT-SQ, NT-SEQ models\u003c\/p\u003e\n\u003cp data-start=\"2170\" data-end=\"2238\"\u003eCompatible with nearly all Suburban 12V furnaces\u003cbr data-start=\"2218\" data-end=\"2221\"\u003eExcludes NT-45S\u003c\/p\u003e\n\u003chr data-start=\"2240\" data-end=\"2243\"\u003e\n\u003ch2 data-section-id=\"i5rncc\" data-start=\"2245\" data-end=\"2292\"\u003eWhen Should You Replace the Control Board?\u003c\/h2\u003e\n\u003cp data-start=\"2293\" data-end=\"2341\"\u003eYou may need the 521099 board if your furnace:\u003c\/p\u003e\n\u003cul data-start=\"2342\" data-end=\"2505\"\u003e\n\u003cli data-section-id=\"ygdt7k\" data-start=\"2342\" data-end=\"2372\"\u003eWill not ignite (no spark)\u003c\/li\u003e\n\u003cli data-section-id=\"1v1q4im\" data-start=\"2373\" data-end=\"2402\"\u003eCycles but does not light\u003c\/li\u003e\n\u003cli data-section-id=\"wxfga1\" data-start=\"2403\" data-end=\"2430\"\u003eBlower runs but no heat\u003c\/li\u003e\n\u003cli data-section-id=\"t741bo\" data-start=\"2431\" data-end=\"2468\"\u003eLocks out after multiple attempts\u003c\/li\u003e\n\u003cli data-section-id=\"x0zq42\" data-start=\"2469\" data-end=\"2505\"\u003eHas intermittent ignition issues\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2507\" data-end=\"2574\"\u003eThis is one of the most common failure points in Suburban furnaces.\u003c\/p\u003e\n\u003chr data-start=\"2576\" data-end=\"2579\"\u003e\n\u003ch2 data-section-id=\"15zhwfb\" data-start=\"2581\" data-end=\"2623\"\u003eWhy Upgrade to the 521099 (3G Board)?\u003c\/h2\u003e\n\u003cul data-start=\"2624\" data-end=\"2802\"\u003e\n\u003cli data-section-id=\"9jtpw\" data-start=\"2624\" data-end=\"2675\"\u003eCombines ignition and fan control into one unit\u003c\/li\u003e\n\u003cli data-section-id=\"e70uzd\" data-start=\"2676\" data-end=\"2719\"\u003eImproves safety with lockout protection\u003c\/li\u003e\n\u003cli data-section-id=\"1sqrdsf\" data-start=\"2720\" data-end=\"2755\"\u003eMore reliable than older boards\u003c\/li\u003e\n\u003cli data-section-id=\"1trjrb2\" data-start=\"2756\" data-end=\"2802\"\u003eSimplifies troubleshooting and replacement\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"2804\" data-end=\"2807\"\u003e\n\u003ch2 data-section-id=\"x9bttf\" data-start=\"2809\" data-end=\"2817\"\u003eFAQ\u003c\/h2\u003e\n\u003cp data-start=\"2819\" data-end=\"2930\"\u003e\u003cstrong data-start=\"2819\" data-end=\"2867\"\u003eWill this replace my 520741 or 520820 board?\u003c\/strong\u003e\u003cbr data-start=\"2867\" data-end=\"2870\"\u003eYes, the 521099 is the direct upgraded replacement for both.\u003c\/p\u003e\n\u003cp data-start=\"2932\" data-end=\"3051\"\u003e\u003cstrong data-start=\"2932\" data-end=\"2978\"\u003eDoes this work with all Suburban furnaces?\u003c\/strong\u003e\u003cbr data-start=\"2978\" data-end=\"2981\"\u003eIt works with most Suburban 12V furnaces, but does NOT fit the NT-45S.\u003c\/p\u003e\n\u003cp data-start=\"3053\" data-end=\"3207\"\u003e\u003cstrong data-start=\"3053\" data-end=\"3097\"\u003eDo I need anything else to install this?\u003c\/strong\u003e\u003cbr data-start=\"3097\" data-end=\"3100\"\u003eIf your current board does not have fan control, you will need a separate wiring harness (sold separately).\u003c\/p\u003e\n\u003cp data-start=\"3209\" data-end=\"3280\"\u003e\u003cstrong data-start=\"3209\" data-end=\"3244\"\u003eCan I use this on a 24V system?\u003c\/strong\u003e\u003cbr data-start=\"3244\" data-end=\"3247\"\u003eNo, this is strictly 12V DC only.\u003c\/p\u003e\n\u003cp data-start=\"3282\" data-end=\"3373\"\u003e\u003cstrong data-start=\"3282\" data-end=\"3306\"\u003eIs there a warranty?\u003c\/strong\u003e\u003cbr data-start=\"3306\" data-end=\"3309\"\u003eYes, this board includes a 3-year manufacturer limited warranty.\u003c\/p\u003e","brand":"RV Furnace Guys","offers":[{"title":"Default Title","offer_id":47949546193137,"sku":null,"price":108.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0784\/4941\/0289\/files\/5210991.jpg?v=1774299887","url":"https:\/\/rvfurnaceguys.com\/products\/suburban-521099-ignition-control-circuit-board-12v-furnace-replacement-520741-520820","provider":"RV Furnace Guys","version":"1.0","type":"link"}