OEM Carrier High & Low Pressure Switch for Model CH14NB03000GAAAA

These OEM pressure switches — part numbers 312926-252 (High Pressure Switch) and 312926-258 (Low Pressure Switch) — are the factory-specified replacements for the Carrier CH14NB03000GAAAA gas furnace. The pressure switch monitors the inducer motor's draft pressure to confirm safe venting conditions before allowing ignition to proceed. A failed pressure switch will cause the furnace to lock out prior to the ignition sequence, leaving the system stuck in a pre-ignition fault with no heat delivered. Common symptoms include a flashing fault code indicating "pressure switch open" or the furnace repeatedly attempting and aborting startup cycles.

• Specs: High Pressure Switch — OEM Part 312926-252 | Low Pressure Switch — OEM Part 312926-258 | Rated to factory W.C. (water column) specification | SPST normally-open contact design | Factory-calibrated trip point for accurate draft proof
• OEM vs Generic: OEM pressure switches are calibrated to the exact W.C. rating required by the CH14NB03000GAAAA's inducer assembly. Generic alternatives frequently carry broader trip-point tolerances, risking nuisance lockouts or, worse, failing to detect a true venting fault — a critical safety concern on any gas appliance.
• Install difficulty: 3/5 — Shut off gas and power before beginning. Tools needed: 1/4" nut driver, flathead screwdriver, manometer (recommended for verifying W.C. after install), and needle-nose pliers for hose barb connections. Inspect rubber tubing and hose barbs for cracks while the switch is removed — replace if stiff or cracked.
• Warranty: 1-year OEM factory warranty. Orders placed before cutoff ship same business day from our warehouse.

Compatibility: Designed specifically for the Carrier CH14NB03000GAAAA furnace platform. Confirm the existing switch's W.C. rating stamped on the switch body matches your unit's data plate specifications before ordering. If you are unsure whether you need the high (312926-252) or low (312926-258) pressure switch, our parts specialists can verify fitment — contact us before ordering. In-stock and ready to ship today.