OEM Carrier High Pressure Switch HK02ZA442 for Model PY1RPA036074ABWA

This OEM high pressure switch (part number HK02ZA442) is the factory-specified replacement for the Carrier PY1RPA036074ABWA packaged rooftop unit. The high pressure switch monitors refrigerant circuit pressure on the high side and cuts out the compressor when pressure exceeds safe operating limits — protecting the compressor from catastrophic over-pressure failure. When this switch fails or trips, the system will typically short-cycle, lock out on a high-pressure fault, or refuse to enter the cooling mode entirely. A nuisance trip that won't reset manually is the most common field complaint.

• Specs: 448 PSI opening pressure | 327 PSI closing pressure | SPST normally closed | Factory Authorized Part — meets exact Carrier Corporation tolerances
• Also included / related: This listing pairs with companion low pressure switch HK02ZB044 (7 PSI open / 22 PSI close, 50" leads) — both switches work in tandem to protect the refrigerant circuit. Replacing both at the same service call is best practice.
• OEM vs Generic: OEM pressure switches are calibrated to exact cut-in and cut-out tolerances at the factory. Off-brand substitutes frequently drift outside spec, causing nuisance lockouts or — worse — failing to protect the compressor at true over-pressure conditions.
• Install difficulty: 2/5 — Recover refrigerant per EPA 608 regulations before disconnecting pressure switch leads on the high-side port. Tools needed: manifold gauge set, wire terminals or heat-shrink connectors, multimeter for continuity check. Always confirm the system is in a recovered/off state before disconnecting wiring.
• Warranty: 1-year OEM factory warranty on all Carrier Factory Authorized Parts. Ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY1RPA036074ABWA packaged rooftop unit. Verify your unit's existing switch cut-out pressure rating on the data plate or wiring diagram before ordering. Need fitment confirmed? Our HVAC parts specialists verify compatibility before you buy — contact us today. In stock — order now and ships today.