OEM Carrier High & Low Pressure Switch — 312926-252 & 312926-258 for Model PH14NB036000AAAA

These are the factory-authorized OEM replacement pressure switches for the Carrier PH14NB036000AAAA heat pump. The high pressure switch (312926-252, 670/470 PSI) monitors refrigerant discharge pressure and cuts power to the compressor the moment pressure exceeds a safe threshold, preventing catastrophic compressor failure. The low pressure switch (312926-258, 55/23 PSI) watches the suction side and shuts the compressor down if refrigerant pressure drops too low — a typical sign of a refrigerant leak or a restriction in the system. Together, these two switches form the refrigerant-side safety circuit. When either fails, the most common symptoms are a system that locks out immediately on startup, short-cycles within seconds, or throws a pressure-fault error code at the thermostat or control board.

• High Pressure Switch Specs: Part# 312926-252 | Cut-out: 670 PSI | Cut-in: 470 PSI | Factory-calibrated SPST normally-closed contact | OEM-matched tolerance
• Low Pressure Switch Specs: Part# 312926-258 | Cut-out: 55 PSI | Cut-in: 23 PSI | Factory-calibrated SPST normally-closed contact | Brass inlet connector with precision diaphragm
• OEM vs Generic: Genuine Carrier OEM switches are factory-set to exact PSI trip points. Aftermarket alternatives often drift ±10–15% from spec, risking nuisance trips or — worse — failing to protect the compressor under true over-pressure conditions.
• Install Difficulty: 3/5 — Refrigerant system must be properly diagnosed before replacement. Tools required: manifold gauge set, multimeter (for continuity test), adjustable wrench, and safety gloves. Always recover refrigerant per EPA Section 608 before opening the refrigerant circuit. Licensed HVAC technician installation is strongly recommended.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Engineered for the Carrier PH14NB036000AAAA 3-ton R-410A heat pump. Verify your unit's data plate model number and existing switch PSI ratings before ordering. Not sure it fits? Contact our parts team — we verify fitment before you buy. Order now and get same-day shipping!