{"product_id":"tempstar-low-pressure-switch-assembly-for-t4h548gkd100-oem-1177594-ships-today","title":"Tempstar Low Pressure Switch Assembly for T4H548GKD100 — OEM 1177594 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM low pressure switch assembly (part number 1177594) protects the Tempstar T4H548GKD100 compressor from operating under dangerously low refrigerant pressure. Wired into the 24V control circuit, the switch opens when suction-side pressure drops below its setpoint — typically caused by low refrigerant charge, a leak, or restricted airflow — and shuts the compressor down before it is damaged. A low pressure switch that fails open will prevent the compressor from running at all, while a stuck-closed switch removes the safety protection entirely. This assembly includes the switch and its factory connector for a direct plug-in replacement.\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\u003eCircuit\u003c\/td\u003e\n\u003ctd\u003eNormally Closed Safety\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump \/ Compressor Protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM Direct Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect OEM fit for the Tempstar T4H548GKD100 heat pump and other ICP-family outdoor units (Heil, Comfortmaker) using the same refrigerant-circuit safety. Verify the part number 1177594 on your existing switch before ordering.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power at the disconnect and breaker, and confirm zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the outdoor unit's service panel to reach the control wiring and refrigerant line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the wiring connections before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the switch leads. The switch is typically a quick-connect Schrader-style fitting; relieve pressure as required and remove the old switch.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Thread on the new 1177594 switch, confirm a leak-free seal, and reconnect the leads per your photos.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify the compressor energizes and that 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 won't start even with adequate refrigerant charge\u003c\/li\u003e\n\u003cli\u003eIntermittent compressor lockouts on a low-pressure fault code\u003c\/li\u003e\n\u003cli\u003eSystem runs without low-pressure protection after a known fault\u003c\/li\u003e\n\u003cli\u003eCorroded, cracked, or leaking switch body or fitting\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day on orders placed before 3 PM CST. 30-day returns on unused parts. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021782204787,"sku":"1177594-GEN","price":34.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048464662899,"sku":"1177594","price":44.2,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-pressure-switch-single-1177594_5d8f4329-eb43-42aa-92cb-02105d816430.jpg?v=1782960530","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-low-pressure-switch-assembly-for-t4h548gkd100-oem-1177594-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}