OEM Carrier SPST High-Fire Pressure Switch HK06WC091 for Model PG8MAA042090AAJA

This OEM pressure switch is the factory-specified replacement for the Carrier PG8MAA042090AAJA gas furnace. The pressure switch is a critical safety device that monitors the negative pressure (vacuum) created by the draft inducer motor. When the inducer reaches proper operating RPM and establishes the correct flue draw, the pressure switch closes — signaling the control board that it is safe to proceed with ignition. If this switch fails or drifts out of calibration, the furnace will lock out before lighting, leaving you with a no-heat call and a flashing fault code.

• Specs: SPST (Single-Pole, Single-Throw) | High-Fire stage | Factory-calibrated W.C. (water column) set point | Honeywell-manufactured Factory Authorized Part | OEM part number HK06WC091
• OEM vs Generic: OEM pressure switches are calibrated to the exact W.C. set point required by your specific furnace model. Generic alternatives often carry loose tolerances that can cause nuisance lockouts, missed opens, or — worse — allow ignition under unsafe flue conditions.
• Install difficulty: 2/5 — Power down the furnace at the disconnect before starting. Tools needed: 1/4" nut driver, needle-nose pliers, and a short length of vacuum tubing if the hose barb needs replacement. Photograph all hose and wiring connections before removal. Swap the pressure tubing and spade connectors directly to the new switch.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed as a direct OEM replacement for the Carrier PG8MAA042090AAJA 80% AFUE gas furnace. Also fits select Bryant and Payne models sharing the same inducer/pressure switch assembly. Always verify the W.C. rating stamped on your existing switch against your unit's data plate before ordering. Our HVAC parts specialists are available to confirm fitment — order with confidence and get your heat back today.