{"product_id":"tempstar-low-pressure-switch-for-t4h348gkd100-oem-1177594-24v-ships-today","title":"Tempstar Low Pressure Switch for T4H348GKD100 — OEM 1177594 24V | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis is the genuine OEM low pressure switch assembly (part number 1177594) for the Tempstar T4H348GKD100 heat pump. The low pressure switch is a refrigerant-side safety control that continuously monitors suction-line pressure. If pressure drops below the factory cut-out threshold — typically caused by a refrigerant leak, low charge, a blocked metering device, or loss of airflow across the indoor coil — the switch opens and interrupts the 24V control circuit to shut down the compressor. This protects the compressor from damaging low-charge and slugging conditions. A failed or sticking switch is a common cause of nuisance lockouts, a compressor that will not start, or short-cycling on the heat-pump system.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\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 (ICP \/ Heil family)\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\u003eRefrigerant low-pressure safety cut-out\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\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eEngineered as a direct-fit replacement for the Tempstar T4H348GKD100 heat pump. The same 1177594 assembly is shared across a range of ICP-built Tempstar, Heil, and Comfortmaker heat pumps of this series. Always confirm against your unit's parts breakdown before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter before touching any wiring.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the condensing unit service panel to expose the control area and refrigerant lines.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the switch wiring and Schrader\/quick-connect location before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the 24V leads, then back off the switch from its refrigerant port (most low pressure switches use a self-sealing Schrader-style fitting, so no recovery is needed; confirm for your model).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Thread the new 1177594 onto the port, snug it, and reconnect the 24V leads per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, start the unit, and confirm the switch holds the circuit closed under normal operating pressure.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eCompressor will not start and the board reports a low-pressure lockout\u003c\/li\u003e\n\u003cli\u003eSystem short-cycles or trips on pressure during normal operation\u003c\/li\u003e\n\u003cli\u003eSwitch fails to reset or shows an open circuit with correct refrigerant charge\u003c\/li\u003e\n\u003cli\u003eVisible corrosion, leakage, or physical damage at the switch body\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\n\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":63021792952691,"sku":"1177594-GEN","price":34.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048465219955,"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_3f5bf020-f53e-4fca-b52c-53418e700e72.jpg?v=1782960548","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-low-pressure-switch-for-t4h348gkd100-oem-1177594-24v-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}