{"product_id":"tempstar-low-pressure-switch-assembly-for-t4h418gkd100-ships-today","title":"Tempstar Low Pressure Switch Assembly for T4H418GKD100 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM low pressure switch assembly (part number 1177594) protects the Tempstar T4H418GKD100 heat pump against loss-of-charge and low-suction conditions. Wired into the 24V control circuit, the switch opens when refrigerant pressure drops below its trip threshold — shutting down the compressor to prevent it from running with insufficient refrigerant. A failed or stuck switch leads to nuisance lockouts, a compressor that won't start, or, if stuck closed, an unprotected compressor at risk of mechanical damage during a low-charge event.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e1177594\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eLow Pressure Switch Assembly\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eTempstar\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl Voltage\u003c\/td\u003e\n\u003ctd\u003e24V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eLoss-of-Charge Protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eT4H418GKD100\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Refrigerant Circuit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eBuilt for the Tempstar T4H418GKD100 and shared ICP \/ Heil \/ Comfortmaker heat pump platforms using the same low-pressure protection assembly. Confirm part number 1177594 and the connection fitting type before installing.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power and verify zero voltage with a multimeter; recover or isolate refrigerant per the switch's connection type.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the outdoor unit service panel to reach the switch and its leads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the wiring and the switch's location on the refrigerant line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the leads and remove the old switch (unthread the Schrader-mount or de-braze per the fitting).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new switch, reconnect the 24V leads per your photo, and leak-check any refrigerant connection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify the compressor starts and the switch holds the circuit closed at normal operating pressure.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eCompressor locks out or won't start with adequate charge\u003c\/li\u003e\n\u003cli\u003eIntermittent nuisance trips on the low-pressure circuit\u003c\/li\u003e\n\u003cli\u003eSwitch fails a continuity test at normal operating pressure\u003c\/li\u003e\n\u003cli\u003eVisible corrosion or damage to the switch body or terminals\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021788397939,"sku":"1177594-GEN","price":34.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048463581555,"sku":"1177594","price":45.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-pressure-switch-single-1177594_5b272de1-c378-4095-8a76-48b9274cc3e9.jpg?v=1782960510","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-low-pressure-switch-assembly-for-t4h418gkd100-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}