OEM Carrier High & Low Pressure Switch Set — 312926-252 & 312926-258 for Model PH13NB048000AAAA

These two OEM refrigerant pressure switches are the factory-authorized replacements for the Carrier PH13NB048000AAAA heat pump. The high pressure switch (312926-252, 670/470 PSI) monitors the high-side refrigerant circuit and cuts power to the compressor if system pressure exceeds the safe upper threshold — protecting the compressor from catastrophic over-pressurization. The low pressure switch (312926-258, 55/23 PSI) guards the low-side circuit, opening the compressor circuit if suction pressure drops dangerously low — a condition caused by refrigerant loss, a blocked filter, or a failed TXV. Together, these switches are the primary refrigerant-circuit safety net on your system. Common failure symptoms include: compressor lockout with a pressure fault code, system short-cycling off on high-side trip, or a no-cool/no-heat condition with no mechanical noise from the compressor.

• High Pressure Switch (312926-252): Cut-out 670 PSIG | Cut-in 470 PSIG | Factory Authorized OEM Part | Carrier part number 312926-252
• Low Pressure Switch (312926-258): Cut-out 55 PSIG | Cut-in 23 PSIG | OEM Sensata / Carrier assembly | Carrier part number 312926-258
• OEM vs Generic: OEM pressure switches are factory-calibrated to exact trip points. Aftermarket switches often exhibit ±10–15% setpoint drift, risking nuisance trips or — worse — allowing the compressor to run outside safe operating pressure, voiding the compressor warranty.
• Install Difficulty: 3/5 — Refrigerant circuit work requires an EPA 608 certification. Tools needed: manifold gauge set, 1/4" flare fittings, wire crimps or spade connectors, multimeter. Always recover refrigerant before removing switches. Photograph wiring before disconnecting. Pressure-test the system after re-installation.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse on orders placed before 3 PM local time.

Compatibility: Engineered specifically for the Carrier PH13NB048000AAAA 4-ton R-410A single-stage heat pump. Verify your unit's data plate refrigerant type and pressure ratings before ordering. Not sure if this is the right part? Our HVAC parts specialists verify fitment before you buy — call or chat today. In stock and ships today.