OEM Carrier Furnace Pressure Switch 1.81" WC SPST — Model PG9MAA048060AFKA (Part# HK06NB123)

This OEM pressure switch is the factory-specified replacement for the Carrier PG9MAA048060AFKA gas furnace. The pressure switch is a critical safety component that monitors the negative pressure (draft) created by the inducer motor before the ignition sequence is allowed to proceed. If the inducer is not running at proper speed or the vent system is blocked, the switch stays open and locks out the furnace — preventing unsafe combustion. When this switch fails or sticks open, you'll typically see the furnace attempt to start, then shut down and display a fault code before any heat is produced.

• Specs: 1.81" inches water column (WC) setpoint | SPST (Single-Pole, Single-Throw) configuration | Two low-voltage spade terminals | Two hose ports for draft tubing connection | OEM Part# HK06NB123
• OEM vs Generic: OEM pressure switches are calibrated to the exact water column setpoint specified by Carrier. Off-brand switches often carry ±10–15% WC tolerance, which can cause nuisance lockouts or — worse — allow ignition under unsafe draft conditions. Don't compromise on safety-critical parts.
• Install difficulty: 2/5 — A straightforward swap for experienced DIYers or any HVAC technician. Tools needed: flathead screwdriver, needle-nose pliers, phone camera (to photograph hose and wire routing before removal). Always power down the furnace at the disconnect before starting. Note which hose port connects to the inducer versus the condensate side.
• Warranty & Shipping: 1-year OEM manufacturer warranty against defects. In stock and ships same business day from our warehouse. Free ground shipping on orders over $99.

Compatibility: Engineered specifically for the Carrier PG9MAA048060AFKA gas furnace. Note that OEM part HK06NB123 has been superseded by HK06NB124 — both are covered under this listing and carry identical 1.81" WC SPST specifications. Always verify your unit's data plate and existing switch markings before ordering. Our fitment team is available to confirm compatibility before you buy — no guesswork required.