OEM Carrier Pressure Switch w/ Bracket 1.81" WC SPST for Model PG9MAB060100AASA

This is the factory OEM replacement pressure switch with mounting bracket (part number HK06NB124) for the Carrier PG9MAB060100AASA gas furnace. The pressure switch monitors negative pressure created by the inducer motor to confirm proper venting before the ignition sequence is allowed to proceed. When this switch fails — or its diaphragm becomes fatigued — the furnace control board cannot verify that the inducer is operating, triggering a lockout. Common symptoms include error code 31, a furnace that attempts ignition and immediately shuts down, or a system that runs the inducer indefinitely without progressing to heat.

• Specs: 1.81" WC (inches water column) set point | SPST (Single-Pole Single-Throw) | 1/4" barb hose connection | Includes factory mounting bracket | Replaces obsolete HK06NB120, HK06NB119, and HK06NB122
• OEM vs Generic: This OEM part is manufactured to Carrier's exact diaphragm deflection and contact specification. Generic aftermarket switches often carry ±5–10% WC tolerances, which can cause nuisance lockouts or, worse, fail to detect true venting faults — a safety risk in gas appliances. OEM is always the correct choice for pressure switches.
• Install difficulty: 2/5 — Power down and lock out the furnace before beginning. Tools needed: 1/4" nut driver, flat-head screwdriver, and needle-nose pliers. Photograph all hose and wiring connections before removal. The bracket mounts to the same factory location. Snap the spade connectors and hose barbs back into position and restore power to verify operation.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed for the Carrier PG9MAB060100AASA gas furnace and fits across 200+ Carrier and Bryant residential furnace models that specify the 1.81" WC SPST pressure switch. Always verify your existing switch's WC rating from your unit's wiring diagram or data plate before ordering. Our parts specialists are available to confirm fitment — reach out before you order and we'll verify your model.