OEM Carrier Draft Pressure Switch 0.18" WC for Model PY3GPAA48090NA (HK06WC061 / HK06MB061)

This OEM Carrier draft pressure proving switch is the factory-authorized replacement for the Carrier PY3GPAA48090NA packaged unit. Rated at 0.18" water column (WC), this SPST switch monitors negative pressure created by the inducer motor to confirm safe draft before allowing the ignition sequence to proceed. When it fails or sticks open, the control board cannot verify proper venting — resulting in a hard lockout with no heat and a blinking fault code. OEM part number HK06WC061 has been superseded by the direct drop-in replacement HK06MB061; both are fulfilled as the same genuine Carrier factory part.

• Specs: 0.18" Water Column (WC) | SPST (Single-Pole Single-Throw) | 24V control circuit | Cross-references Honeywell IS20224-5236 | Fits Carrier, Bryant, and Payne platforms
• OEM vs Generic: OEM switches are calibrated to exact ±0.01" WC tolerances at the factory. Off-brand substitutes frequently drift out of spec, causing nuisance lockouts or — worse — allowing ignition under unsafe draft conditions.
• Install difficulty: 2/5 — Power down the unit at the disconnect and thermostat before beginning. Tools needed: 1/4" nut driver, flathead screwdriver, and a manometer or magnehelic gauge to verify draft after replacement. Photograph the pressure tubing routing before disconnecting. Single hose port; confirm tubing is free of cracks or blockages before reinstalling.
• Warranty: 1-year OEM manufacturer warranty. In-stock orders ship the same business day from our warehouse.

Compatibility: Engineered as the direct OEM replacement for Carrier model PY3GPAA48090NA packaged gas/electric units. Also fits select Bryant and Payne models sharing the same inducer assembly and 0.18" WC pressure requirement — verify your unit's data plate and existing switch rating before ordering. Our HVAC specialists are available to confirm fitment prior to purchase.