{"product_id":"haywardfdheaterhighlimitkitfdxlhli1930hppfdxlhli1930","title":"Hayward FD Heater High Limit Kit | FDXLHLI1930","description":"\u003cdiv class=\"product-description\"\u003e\n\n  \u003ch2\u003eHayward FDXLHLI1930 High Limit Switch Kit (135°F) for Universal H-Series Low NOx FD Heaters\u003c\/h2\u003e\n\n  \u003cp\u003e\n    The Hayward \u003cstrong\u003eFDXLHLI1930\u003c\/strong\u003e is a genuine OEM \u003cstrong\u003ehigh limit switch kit\u003c\/strong\u003e rated at \u003cstrong\u003e135°F\u003c\/strong\u003e for\n    Hayward \u003cstrong\u003eUniversal H-Series Low NOx\u003c\/strong\u003e “FD” pool heaters. The high limit is a critical safety device that helps protect the\n    heater by shutting it down if internal water temperature rises beyond a safe threshold—most commonly caused by low water flow, restricted\n    circulation, or scale buildup.\n  \u003c\/p\u003e\n\n  \u003ch3\u003eFits \/ Compatibility\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eHayward Universal H-Series Low NOx FD heaters:\n      \u003cstrong\u003eH150FDN\u003c\/strong\u003e, \u003cstrong\u003eH150FDP\u003c\/strong\u003e, \u003cstrong\u003eH200FDN\u003c\/strong\u003e, \u003cstrong\u003eH200FDP\u003c\/strong\u003e,\n      \u003cstrong\u003eH250FDN\u003c\/strong\u003e, \u003cstrong\u003eH250FDP\u003c\/strong\u003e, \u003cstrong\u003eH300FDN\u003c\/strong\u003e, \u003cstrong\u003eH300FDP\u003c\/strong\u003e,\n      \u003cstrong\u003eH350FDN\u003c\/strong\u003e, \u003cstrong\u003eH350FDP\u003c\/strong\u003e, \u003cstrong\u003eH400FDN\u003c\/strong\u003e, \u003cstrong\u003eH400FDP\u003c\/strong\u003e\n    \u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eWhat It Fixes\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eHeater shutting down due to a failed\/out-of-spec high limit switch\u003c\/li\u003e\n    \u003cli\u003eIntermittent heat cycles caused by a high limit that opens unpredictably\u003c\/li\u003e\n    \u003cli\u003eCorroded, damaged, or heat-stressed high limit components found during service\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eBefore Replacing the High Limit\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eCheck and clean the \u003cstrong\u003efilter\u003c\/strong\u003e and \u003cstrong\u003epump basket\u003c\/strong\u003e (low flow is the #1 cause of high-limit trips).\u003c\/li\u003e\n    \u003cli\u003eVerify all \u003cstrong\u003evalves\u003c\/strong\u003e are open and any \u003cstrong\u003ebypass\u003c\/strong\u003e is set correctly.\u003c\/li\u003e\n    \u003cli\u003eConfirm adequate \u003cstrong\u003ewater flow rate\u003c\/strong\u003e through the heater.\u003c\/li\u003e\n    \u003cli\u003eInspect for \u003cstrong\u003escale\u003c\/strong\u003e in the heater if water chemistry has been out of balance.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eWhat’s Included\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eHigh limit switch kit (135°F) for compatible FD heater applications\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eInstallation Notes\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTurn off power\u003c\/strong\u003e to the heater at the breaker before servicing.\u003c\/li\u003e\n    \u003cli\u003eLabel or photograph wire positions before removal for correct reinstallation.\u003c\/li\u003e\n    \u003cli\u003eIf the heater continues to trip after replacement, diagnose the underlying \u003cstrong\u003eflow\/scale\u003c\/strong\u003e issue to prevent repeat shutdowns.\u003c\/li\u003e\n    \u003cli\u003eInstallation is recommended for a qualified service technician.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eSpecs (Quick Reference)\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003ePart Number: \u003cstrong\u003eFDXLHLI1930\u003c\/strong\u003e\n\u003c\/li\u003e\n    \u003cli\u003eType: \u003cstrong\u003eHigh Limit Switch Kit\u003c\/strong\u003e\n\u003c\/li\u003e\n    \u003cli\u003eTemperature Rating: \u003cstrong\u003e135°F\u003c\/strong\u003e\n\u003c\/li\u003e\n    \u003cli\u003eApplication: \u003cstrong\u003eUniversal H-Series Low NOx FD Heaters\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eRelated Products\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=FDXLHLI1930\"\u003eHayward FDXLHLI1930 High Limit Switch Kit (search)\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=FDXLWPS1930\"\u003eHayward FD Heater Water Pressure Switch (search)\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=FDXLTER1931\"\u003eHayward FD Heater Thermistor \/ Temp Sensor (search)\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=Hayward%20H-Series%20FD%20heater%20parts\"\u003eHayward Universal H-Series FD Heater Parts (search)\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"https:\/\/aquapoolsupply.com\/search?q=pool%20filter%20pressure%20gauge\"\u003eFilter Pressure Gauges (search)\u003c\/a\u003e\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr\u003e\n\n  \u003ch3\u003eMaintenance Tips\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eBackwash\/clean the filter when pressure rises 8–10 PSI above your clean starting pressure.\u003c\/li\u003e\n    \u003cli\u003eMaintain balanced water chemistry to reduce scale in the heat exchanger.\u003c\/li\u003e\n    \u003cli\u003eIf the heater trips on safety limits repeatedly, address circulation problems first—replacing switches won’t fix chronic low flow.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n\u003c\/div\u003e","brand":"Hayward","offers":[{"title":"Default Title","offer_id":52589938311484,"sku":"FDXLHLI1930","price":58.75,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0736\/3280\/9276\/files\/hayward-fd-heater-high-limit-kit-fdxlhli1930-heater-parts-2891452.jpg?v=1772790147","url":"https:\/\/aquapoolsupply.com\/products\/haywardfdheaterhighlimitkitfdxlhli1930hppfdxlhli1930","provider":"Aqua Pool Supply","version":"1.0","type":"link"}