OEM Carrier High & Low Pressure Switch Kit 312926-252 / 312926-258 for Model PH14NB042000AAAA

These two OEM Carrier pressure switches are the factory-specified refrigerant safety controls for the Carrier PH14NB042000AAAA heat pump. The high pressure switch (312926-252, 670/470 PSI) monitors refrigerant discharge pressure and trips the compressor offline if pressure exceeds safe operating limits — protecting the compressor from catastrophic over-pressure failure. The low pressure switch (312926-258, 55/23 PSI) guards against low-charge or loss-of-refrigerant conditions by cutting compressor power before pressures drop to a damaging level. When either switch fails or trips without resetting, the system typically enters a hard lockout: the unit will not start, the thermostat call goes unanswered, and fault codes pointing to high- or low-pressure lockout appear on the control board.

• Part Numbers & Specs: High Pressure Switch — OEM #312926-252 | Cut-out: 670 PSI / Cut-in: 470 PSI | Low Pressure Switch — OEM #312926-258 | Cut-out: 55 PSI / Cut-in: 23 PSI | Factory Authorized Parts, Carrier Corporation
• OEM vs Generic: These are genuine Carrier Factory Authorized Parts (FAP) with precision-calibrated diaphragms and exact PSI set points. Generic aftermarket switches often carry ±10–15% pressure tolerances, risking nuisance trips or, worse, failing to protect the compressor at the correct threshold.
• Install Difficulty: 3/5 — Refrigerant circuit work requires an EPA Section 608 certified technician. Recover refrigerant before removing switches. Tools needed: manifold gauge set, refrigerant recovery unit, adjustable wrench, multimeter for continuity verification. Photograph existing wiring before disconnecting.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse. Free shipping on orders over $99.

Compatibility: Designed as direct OEM replacements for Carrier PH14NB042000AAAA heat pump units. Always verify refrigerant type, cut-in/cut-out PSI ratings, and connector type against your unit's data plate before ordering. Not sure? Our HVAC parts specialists verify fitment before you buy — order today and get it shipped out the same business day.