OEM Carrier High Pressure Switch 670/470 PSI for Model PH4ANG018000BAAA

This OEM high pressure switch (part# 312926-252) is the factory-specified safety control replacement for the Carrier PH4ANG018000BAAA packaged heat pump unit. The high pressure switch continuously monitors refrigerant circuit pressure and opens the control circuit whenever system pressure exceeds safe operating thresholds — protecting the compressor from catastrophic over-pressurization damage. When this switch fails or trips without resetting, common symptoms include the system locking out on a high-pressure fault, the compressor shutting down unexpectedly, or the unit failing to cool or heat entirely. Always verify whether nuisance tripping is caused by a failed switch or an underlying refrigerant charge or airflow issue before replacing.

• Specs: Cut-out: 670 PSI | Cut-in (reset): 470 PSI | Factory-matched trip points | SPST normally-closed configuration | Rated for R-410A refrigerant systems
• OEM vs Generic: This is a genuine Carrier OEM part built to exact factory trip-point tolerances. Aftermarket switches can drift outside calibrated PSI thresholds, risking either nuisance lockouts or — more dangerously — failure to protect the compressor under true over-pressure conditions.
• Install difficulty: 3/5 — Refrigerant circuit work must be performed by an EPA Section 608 certified technician. Tools needed: manifold gauge set, torque wrench, leak detector. Always recover refrigerant before opening the high-side circuit. Photograph and label wiring before disconnecting.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Designed for the Carrier PH4ANG018000BAAA packaged heat pump. Verify the 670/470 PSI trip-point rating on your unit's existing switch or service manual before ordering. Cross-reference part number 312926-252 to confirm fitment. Have questions? Our HVAC parts specialists verify compatibility before you order — reach out via chat or phone. In stock and ships today.