OEM Carrier Draft Pressure Switch 0.18" WC for Model PY4GNAB24040NA

This OEM draft proving pressure switch is the factory-specified replacement for the Carrier PY4GNAB24040NA packaged unit. The pressure switch monitors negative pressure created by the inducer motor to confirm proper venting before allowing the ignition sequence to proceed. When this switch fails or sticks open, the control board cannot verify safe draft conditions — resulting in a furnace that locks out before ignition, flashes a pressure switch fault code, or refuses to start the heating cycle altogether.

• Specs: 0.18" W.C. (water column) set point | Single-pole, normally open | Honeywell-manufactured | OEM part HK06WC061 / updated replacement HK06MB061 — cross-reference IS20224-5236
• OEM vs Generic: This is a genuine OEM-spec part manufactured to Carrier's exact W.C. rating tolerance. Off-spec aftermarket switches can trip too early or too late, causing nuisance lockouts or, worse, allowing ignition under unsafe draft conditions.
• Install difficulty: 2/5 — Disconnect power to the unit before servicing. Tools needed: 1/4" nut driver, needle-nose pliers, and a manometer (recommended to verify draft pressure after replacement). Inspect the rubber hose port for cracks or blockages before installing the new switch.
• Warranty & Shipping: 1-year OEM warranty. In stock — ships same business day from our warehouse.

Compatibility: Engineered for Carrier PY4GNAB24040NA packaged units. This part supersedes OEM number HK06WC061 and is fulfilled as HK06MB061 — both numbers are accepted for this application. Also cross-compatible with select Bryant and Payne models sharing the same 0.18" W.C. specification. Verify the W.C. rating on your existing switch before ordering. Have questions about fitment? Our HVAC parts specialists confirm compatibility before you buy — order with confidence and get same-day shipping today.