OEM Carrier High & Low Pressure Switch Kit (312926-252 & 312926-258) for Model PH3ANA018000BBAA

This factory-matched OEM pressure switch kit contains both the High Pressure Switch (312926-252, rated 670/470 PSI) and the Low Pressure Switch (312926-258, rated 55/23 PSI) for the Carrier PH3ANA018000BBAA packaged heat pump unit. Pressure switches are critical refrigerant-circuit safety controls: the high-pressure switch opens when system pressure exceeds the safe upper threshold, shutting down the compressor to prevent catastrophic failure; the low-pressure switch opens when pressure drops too low — caused by a refrigerant leak, blocked metering device, or dirty filter — protecting the compressor from running in a starved-refrigerant condition. Symptoms of failure include sudden system lockout, error codes on the thermostat or control board, short cycling, or a unit that starts briefly then shuts off within seconds.

• Specs — High Pressure Switch (312926-252): Cut-out 670 PSI | Cut-in 470 PSI | Factory Authorized OEM Part | Replaces: 312926252
• Specs — Low Pressure Switch (312926-258): Cut-out 55 PSI | Cut-in 23 PSI | Factory Authorized OEM Part | Sensata / Wilspec compatible cross-reference
• OEM vs Generic: OEM switches are factory-calibrated to exact PSI setpoints for the PH3ANA018000BBAA refrigerant circuit. Generic alternatives can carry ±10–15% PSI tolerance, risking nuisance trips or — more dangerously — failure to trip when needed, leading to compressor damage.
• Install Difficulty: 3/5 — Refrigerant circuit work requires EPA 608 certification. Always recover refrigerant before opening the circuit. Tools needed: manifold gauge set, recovery machine, torque wrench, multimeter. Photograph all wiring before disconnecting. Test system pressures after replacement to confirm proper setpoint operation.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse.

Compatibility: This kit is designed for the Carrier PH3ANA018000BBAA packaged heat pump. Verify part numbers 312926-252 and 312926-258 against your unit's wiring diagram and data plate before ordering. Our fitment team is available to confirm compatibility before you buy — order with confidence and get back up and running fast.