OEM Carrier Furnace Pressure Switch 1.81" WC SPST for Model PG9MAA048080AFKA

This OEM-spec pressure switch is the factory-matched replacement for the Carrier PG9MAA048080AFKA gas furnace, carrying part number HK06NB123. The pressure switch is a critical safety interlock that monitors inducer motor draft before allowing ignition to proceed. When the inducer creates the correct negative pressure in the flue, the switch closes and signals the control board to advance the ignition sequence. A failed pressure switch will cause the furnace to lock out on a fault code before the igniter ever fires — leaving you with a cold house and a blinking LED error code.

• Specs: 1.81" WC (inches water column) setpoint | SPST (single-pole, single-throw) configuration | Standard 3/16" hose port and quick-connect terminals | Factory-matched switching accuracy
• OEM vs Generic: OEM pressure switches are calibrated to the exact setpoint for your furnace's inducer. Off-spec generic switches can trip too early or too late, causing nuisance lockouts or — more dangerously — allowing operation under improper draft conditions.
• Install difficulty: 2/5 — Power off the furnace at the breaker and gas shutoff before starting. Tools needed: flathead screwdriver, needle-nose pliers, and a short length of replacement tubing if the existing hose is cracked. Always inspect the rubber hose connected to the switch — a cracked hose is often the real culprit and costs under $1 to replace.
• Warranty: 1-year OEM factory warranty against manufacturing defects. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed for the Carrier PG9MAA048080AFKA 80% AFUE gas furnace. Note that OEM part HK06NB123 has been superseded by HK06NB124 — both maintain the same 1.81" WC specification and are functionally identical. Verify your existing switch's WC rating on the data plate or switch body before ordering. Not sure it fits? Contact our team for free fitment verification before you buy — we confirm compatibility on every order.