OEM Carrier High & Low Pressure Switch for Model CH13NA03700GACAA

These OEM pressure switches — 312926-252 (High Pressure Switch) and 312926-258 (Low Pressure Switch) — are the factory-specified replacements for the Carrier CH13NA03700GACAA condensing unit. Pressure switches prove that the inducer motor has created adequate draft before allowing the ignition sequence to proceed. When either switch fails or sticks open, the control board sees an unsafe condition and locks out the system entirely — resulting in no heat and a blinking fault code typically indicating a pressure switch fault. Common failure symptoms include the inducer running continuously with no ignition, nuisance lockouts on cold days, or water-logged tubing collapsing the switch diaphragm.

• Specs: 312926-252 — High Pressure Switch | 312926-258 — Low Pressure Switch | Factory-calibrated W.C. (water column) rating | SPNO (normally open) contacts | Fits standard 3/16" hose barb inducer port
• OEM vs Generic: OEM switches are calibrated to the exact W.C. rating specified by Carrier's engineers. Generic pressure switches frequently carry wide tolerances that can allow unsafe draft conditions to go undetected or cause nuisance lockouts, leading to unnecessary service calls.
• Install Difficulty: 2/5 — Power down and tag out the unit before beginning. Inspect and clear the condensate drain and rubber hose tubing for blockages or cracks before replacing the switch — a clogged drain is the most common root cause of switch failure. Tools needed: 1/4" nut driver, flathead screwdriver, and a manometer or magnehelic gauge to verify W.C. rating after install.
• Warranty: 1-year OEM factory warranty. Orders ship the same business day from our climate-controlled warehouse.

Compatibility: Both switches are engineered specifically for the Carrier CH13NA03700GACAA condensing unit. Always cross-reference the OEM part number printed on your existing switch before ordering to confirm whether you need the high-pressure (312926-252) or low-pressure (312926-258) switch for your application. Our parts specialists are available to verify fitment before you place your order — same-day shipping guaranteed on all in-stock OEM components.