OEM Carrier High Pressure Switch HK02ZA442 for Model PY1REA048115AAWA

This OEM high pressure switch (part number HK02ZA442) is the factory-specified refrigerant-side safety control for the Carrier PY1REA048115AAWA packaged rooftop unit. Mounted in the high-side refrigerant circuit, it monitors discharge pressure and trips the compressor circuit open when pressure exceeds safe operating limits — protecting the compressor from catastrophic damage due to overcharge, condenser fouling, or blocked airflow. A failed or out-of-calibration pressure switch causes nuisance high-pressure lockouts, failure to cool, or a system that short-cycles and trips on repeated fault codes. This listing also covers the companion low-pressure switch HK02ZB044 (7#OPN / 22#CLS, 50" lead), sold separately — confirm your fault code to order the correct switch.

• Part Numbers: HK02ZA442 (High Pressure Switch — primary) | HK02ZB044 (Low Pressure Switch — companion) | Replaces legacy part HK02ZA439
• Specs — HK02ZA442: 448 PSI opening pressure | 327 PSI closing pressure | SPST normally closed | Factory Authorized Part — meets exact Carrier engineering tolerances
• OEM vs Generic: OEM pressure switches are calibrated to precise trip points at the factory. Aftermarket substitutes frequently deviate by ±10–15 PSI, risking either nuisance trips that reduce runtime or, worse, insufficient compressor protection that leads to premature failure.
• Install Difficulty: 3/5 — Refrigerant circuit work requires EPA 608 certification. Recover refrigerant before disconnecting the high-side port. Tools needed: manifold gauge set, 1/4" flare fittings, wire terminals, multimeter. Verify continuity of replacement switch before recharging system.
• Warranty: 1-year OEM factory warranty. Orders placed by 3 PM local time ship same business day from our warehouse.

Compatibility: Factory-matched for the Carrier PY1REA048115AAWA packaged rooftop unit (4-ton, 115,000 BTU gas heat). Always cross-reference the data plate part number before ordering. Our technical team is available to verify fitment — contact us before you buy if you have any doubt.