{"product_id":"5d51-78-copeland-comfort-control-white-rodgers-fan-limit-ctrl-11-insert","title":"5D51-78 Copeland Comfort Control (White Rodgers) FAN\/LIMIT CTRL, 11\" INSERT","description":"\u003ch1\u003e5D51-78 Copeland Comfort Control (White Rodgers) FAN\/LIMIT CTRL, 11\" INSERT\u003c\/h1\u003e\n\u003cstyle\u003e\na {\n    text-decoration: none;\n    color: #464feb;\n}\ntr th, tr td {\n    border: 1px solid #e6e6e6;\n}\ntr th {\n    background-color: #f5f5f5;\n}\n\u003c\/style\u003e\n\u003cdiv\u003e\n\u003cp\u003eThe \u003cstrong\u003e5D51-78 Fan \u0026amp; Limit Control (White-Rodgers \/ Copeland Comfort Control)\u003c\/strong\u003e is a combination furnace control designed to regulate blower fan operation and provide high-temperature safety protection in residential and light commercial heating systems. Featuring an \u003cstrong\u003e11-inch insertion element\u003c\/strong\u003e, this control automatically cycles the blower based on plenum temperature while protecting the furnace from overheating through its integrated limit control function.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eCross-Reference\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e5D51-78\u003c\/li\u003e\n\u003cli\u003e5D5178\u003c\/li\u003e\n\u003cli\u003eWhite-Rodgers 5D51-78\u003c\/li\u003e\n\u003cli\u003eCopeland Comfort Control 5D51-78\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eDirect OEM\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhite-Rodgers 5D51-78\u003c\/strong\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eCompatible Brands\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eWhite-Rodgers\u003c\/li\u003e\n\u003cli\u003eEmerson\u003c\/li\u003e\n\u003cli\u003eCopeland\u003c\/li\u003e\n\u003cli\u003eYork\u003c\/li\u003e\n\u003cli\u003eColeman\u003c\/li\u003e\n\u003cli\u003eLuxaire\u003c\/li\u003e\n\u003cli\u003eGoodman\u003c\/li\u003e\n\u003cli\u003eRheem\u003c\/li\u003e\n\u003cli\u003eUniversal Warm Air Furnace Applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eApplication\u003c\/h3\u003e\n\u003cp\u003eUsed in forced-air furnaces to:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eControl blower fan operation\u003c\/li\u003e\n\u003cli\u003eProvide furnace high-limit safety protection\u003c\/li\u003e\n\u003cli\u003ePrevent circulation of cold air during startup\u003c\/li\u003e\n\u003cli\u003eAutomatically cycle the blower during heating operation\u003c\/li\u003e\n\u003cli\u003eProtect heat exchangers from overheating\u003c\/li\u003e\n\u003cli\u003eMaintain proper furnace operating temperatures\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eRelated Components\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFan \u0026amp; Limit Control\u003c\/li\u003e\n\u003cli\u003eHigh Limit Switch\u003c\/li\u003e\n\u003cli\u003eFan Switch\u003c\/li\u003e\n\u003cli\u003eFurnace Control Board\u003c\/li\u003e\n\u003cli\u003eBlower Relay\u003c\/li\u003e\n\u003cli\u003eBlower Motor\u003c\/li\u003e\n\u003cli\u003eTransformer\u003c\/li\u003e\n\u003cli\u003eThermostat\u003c\/li\u003e\n\u003cli\u003eTemperature Control Dial\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eTechnician Notes\u003c\/h3\u003e\n\u003cp\u003eThe 5D51-78 is a \u003cstrong\u003ecombination fan and limit control\u003c\/strong\u003e equipped with an \u003cstrong\u003e11-inch insertion element\u003c\/strong\u003e for furnaces requiring deeper plenum penetration than standard controls. This all-in-one control manages blower operation while providing overtemperature protection to help safeguard the heat exchanger and furnace components.\u003c\/p\u003e\n\u003cp\u003eAlways verify insertion length, mounting dimensions, temperature settings, and electrical ratings before replacement. Improper insertion depth can affect fan cycling and temperature sensing accuracy.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eCommon Symptoms of Failure\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBlower fan runs continuously\u003c\/li\u003e\n\u003cli\u003eBlower fails to start\u003c\/li\u003e\n\u003cli\u003eFurnace overheats\u003c\/li\u003e\n\u003cli\u003eHigh-limit shutdowns\u003c\/li\u003e\n\u003cli\u003eShort cycling\u003c\/li\u003e\n\u003cli\u003eDelayed blower operation\u003c\/li\u003e\n\u003cli\u003eInconsistent heating performance\u003c\/li\u003e\n\u003cli\u003eExcessive furnace temperatures\u003c\/li\u003e\n\u003cli\u003eNo heat output\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eInstallation Tips\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eDisconnect power before servicing.\u003c\/li\u003e\n\u003cli\u003eLabel all wiring before removal.\u003c\/li\u003e\n\u003cli\u003eVerify the 11-inch insertion length matches the original control.\u003c\/li\u003e\n\u003cli\u003eFully insert the sensing element into the plenum.\u003c\/li\u003e\n\u003cli\u003eInspect terminals for corrosion or overheating.\u003c\/li\u003e\n\u003cli\u003eVerify blower motor operation and amperage.\u003c\/li\u003e\n\u003cli\u003eConfirm fan and limit settings after installation.\u003c\/li\u003e\n\u003cli\u003eTest operation through a complete heating cycle.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003chr\u003e\n\u003ch3\u003eRecommended Inspection Items\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBlower motor condition\u003c\/li\u003e\n\u003cli\u003eAir filter restriction\u003c\/li\u003e\n\u003cli\u003eHeat exchanger temperature rise\u003c\/li\u003e\n\u003cli\u003eBlower relay operation\u003c\/li\u003e\n\u003cli\u003eWiring terminals\u003c\/li\u003e\n\u003cli\u003eFurnace control board\u003c\/li\u003e\n\u003cli\u003eSupply and return airflow\u003c\/li\u003e\n\u003cli\u003eVenting system condition\u003c\/li\u003e\n\u003cli\u003eBlower wheel cleanliness\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Neuco","offers":[{"title":"Default Title","offer_id":45887291064386,"sku":"5D51-78","price":238.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1071\/8320\/files\/Screenshot2026-11-02220322_6f8b130e-7b1f-41c6-aaf8-b36ba0b1e398.png?v=1793682553","url":"https:\/\/hvacpartstore.com\/products\/5d51-78-copeland-comfort-control-white-rodgers-fan-limit-ctrl-11-insert","provider":"HVACpartstore","version":"1.0","type":"link"}