OEM Carrier High & Low Pressure Switch Set HK02ZA395 / HK02ZB044 for Model PH2PNB042000AB

This OEM pressure switch kit contains both the high-pressure safety switch (HK02ZA395) and the low-pressure switch (HK02ZB044) factory-specified for the Carrier PH2PNB042000AB heat pump. Together, these switches monitor refrigerant pressure on both the high and low sides of the refrigerant circuit. When either switch detects an out-of-range pressure condition, it opens the circuit and locks out the system to prevent compressor damage. Common failure symptoms include the unit going into lockout after startup, short-cycling within the first few minutes of operation, or a complete no-start condition with a pressure fault code on the thermostat or control board.

• Specs — HK02ZA395 (High Pressure Switch): Opens at 395 PSI | Closes at 295 PSI | 1/8" NPT thread | 240 VAC | Sensata PS80-03-0018 platform | Replaces 312926-217, HK02ZA380, HK02ZA396, and related superseded part numbers
• Specs — HK02ZB044 (Low Pressure Switch): Opens at 7 PSI | Closes at 22 PSI | 24V | 50" lead wire | OEM direct drop-in replacement | Made in Mexico
• OEM vs Generic: OEM Carrier pressure switches are calibrated to exact factory cut-in/cut-out tolerances. Aftermarket alternatives frequently deviate from set-point specs, causing nuisance lockouts or, worse, allowing the compressor to operate outside safe pressure limits — risking costly compressor failure.
• Install difficulty: 2/5 — Recover refrigerant per EPA 608 regulations before removing either switch from the refrigerant circuit. Tools needed: refrigerant recovery machine, manifold gauge set, 1" open-end wrench, thread seal tape, multimeter. Always verify pressure set points match unit data plate before installing. Replace both switches as a set when one fails to avoid a repeat call.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse.

Compatibility: This switch kit is factory-specified for the Carrier PH2PNB042000AB heat pump. Verify refrigerant type and pressure ratings on your unit's data plate before ordering. Our technical team is available to confirm fitment — contact us before you order if you have any questions. In stock and ready to ship today.