OEM Carrier High & Low Pressure Switch Kit — 312926-252 & 312926-258 for PH13NB03700GAAAA

This factory-matched OEM pressure switch kit includes both the 312926-252 High Pressure Switch (670–470 PSI) and the 312926-258 Low Pressure Switch (55–23 PSI), the exact components specified by Carrier for the PH13NB03700GAAAA split-system heat pump. These refrigerant-side safety switches monitor system pressure in real time and cut power to the compressor circuit the instant an out-of-range condition is detected — preventing catastrophic compressor failure caused by refrigerant overcharge, loss of charge, blocked airflow, or a failing metering device. When either switch trips and fails to auto-reset, you'll typically see a hard lockout fault on the thermostat or control board, with the system failing to maintain temperature.

• Specs — High Pressure Switch (312926-252): Cut-out 670 PSI | Auto-reset at 470 PSI | Factory Authorized Part | Direct refrigerant-circuit mount
• Specs — Low Pressure Switch (312926-258): Cut-out 55 PSI | Auto-reset at 23 PSI | Factory Authorized Part | Pre-wired leads for drop-in replacement
• OEM vs Generic: OEM Carrier pressure switches are calibrated to exact factory cut-out and reset pressures. Generic alternatives frequently carry wider tolerances, allowing marginal pressure conditions to go undetected and shortening compressor lifespan significantly.
• Install Difficulty: 3/5 — Refrigerant-side work requires an EPA 608 certification. Recover refrigerant before replacing switches. Tools needed: manifold gauge set, refrigerant recovery unit, wire strippers, multimeter. Photograph all wiring before disconnecting. Recheck system pressures after reinstallation.
• Warranty: 1-year OEM factory warranty on both switches. Ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier PH13NB03700GAAAA split-system heat pump. Verify part numbers against your unit's wiring diagram and data plate before ordering. Need fitment confirmation? Our HVAC parts specialists verify compatibility before you buy — order now and get same-day shipping on in-stock OEM parts.