OEM Carrier High & Low Pressure Switch Kit (312926-252 / 312926-258) for PH15NA042000BAAA

This factory-matched OEM pressure switch pair is the correct replacement for the Carrier PH15NA042000BAAA heat pump. The High Pressure Switch (312926-252) monitors refrigerant discharge pressure and cuts power to the compressor if it exceeds the 670 psig trip point (resetting at 470 psig), protecting the system from catastrophic compressor failure. The companion Low Pressure Switch (312926-258) guards against dangerously low suction pressure caused by refrigerant loss or airflow blockage. When either switch fails or trips without resetting, the unit will lock out on a fault code — commonly misdiagnosed as a refrigerant or board issue.

• Part Numbers: 312926-252 (High Pressure Switch, 670/470 psig) | 312926-258 (Low Pressure Switch) | Genuine Carrier OEM — exact factory specification
• OEM vs Generic: OEM switches use factory-calibrated trip and reset setpoints. Aftermarket switches frequently carry wider tolerances, risking compressor over-pressure events or nuisance lockouts that mask real refrigerant issues.
• Install Difficulty: 3/5 — Refrigerant circuit work must be performed by an EPA 608-certified technician. Tools required: manifold gauge set, RATCHET set, insulated electrical connectors, multimeter. Always recover refrigerant before disconnecting high-side switch; low-side can often be replaced at low pressure with caution.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Engineered specifically for the Carrier PH15NA042000BAAA 3.5-ton R-410A heat pump. Verify OEM part numbers 312926-252 and 312926-258 against your unit's data plate and wiring diagram before installation. Not sure it fits? Our HVAC parts specialists verify fitment before you order — no guesswork, no returns. Order now and ship today.