OEM Carrier Dual Pressure Switch Assembly HK06NB021 for Model PG96VAT66120DAAA

This is the factory OEM Dual Pressure Switch Assembly (part number HK06NB021, also cross-referenced as HK06MB021) designed for the Carrier PG96VAT66120DAAA 96% AFUE packaged gas furnace. The pressure switch is a critical safety component that monitors the inducer motor's draft performance before allowing the ignition sequence to proceed. When the switch fails — or when a clogged port, collapsed hose, or weak inducer causes it to stay open — the furnace control board locks out the heating cycle entirely. Common symptoms include a blinking fault code for "pressure switch open," no ignition attempt, or a furnace that starts the inducer but immediately shuts down without progressing to ignition.

• Part Numbers: OEM primary HK06NB021 | Upgraded OEM successor HK06MB021 | Secondary gas switch HK02LB008 — both switches in the dual-switch assembly are included
• OEM vs Generic: OEM Carrier pressure switches are factory-calibrated to exact water column (W.C.) trip points for the PG96VAT66120DAAA's inducer and heat exchanger. Aftermarket switches can have loose W.C. tolerances, causing nuisance lockouts or — more dangerously — allowing ignition under marginal draft conditions.
• Install Difficulty: 3/5 — Requires disconnecting low-voltage wiring harness, removing rubber hose ports, and confirming hose routing matches original. Tools needed: #2 Phillips screwdriver, 1/4" nut driver, manometer (recommended to verify draft before reinstalling). Always clear fault codes after installation.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility & Shipping: Verified for Carrier model PG96VAT66120DAAA packaged gas furnace. Cross-references: HK06MB021 (updated OEM supersession), HK02LB008 (secondary LP/gas pressure switch). Verify your unit's model data plate and existing switch W.C. ratings before ordering. Not sure if this is the right part? Our HVAC parts specialists confirm fitment before you buy — in stock and ready to ship today.