OEM Carrier Furnace Pressure Switch 0.18" W.C. for Model PY4GNAB48090AA — Part # HK06WC061

This is the OEM factory-specified draft proving pressure switch for the Carrier PY4GNAB48090AA packaged unit. The pressure switch monitors negative pressure generated by the inducer motor to confirm that the heat exchanger flue path is clear before allowing ignition to proceed. When this switch fails or sticks open, the control board never receives the "inducer proven" signal — resulting in a no-heat lockout, repeated ignition attempts with no flame, or an error code indicating a pressure switch fault. Replacing it with the correct OEM-rated 0.18" W.C. switch restores factory-spec operation immediately.

• Specs: 0.18" W.C. (inches water column) set point | Single-port draft proving type | Normally open | Factory-matched to Carrier PY4GNAB48090AA inducer pressure | OEM Part # HK06WC061 (superseded by HK06MB061)
• OEM vs Generic: OEM pressure switches are calibrated to exact W.C. tolerances at the factory. Generic alternatives often carry ±0.05" W.C. variance — enough to cause nuisance lockouts in cold-start conditions or fail to trip when a genuine venting restriction exists.
• Install Difficulty: 2/5 — Turn off gas and 24V control power before beginning. Tools needed: 1/4" nut driver, flat-head screwdriver, and a manometer or magnehelic gauge to verify set point post-install. Disconnect the rubber port tube and two spade terminals, swap the switch, reconnect, and power up. Always verify draft pressure at the port before condemning the switch.
• Warranty & Shipping: 1-year OEM manufacturer warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY4GNAB48090AA packaged gas/electric unit. Also cross-references with compatible Bryant and Payne models requiring the 0.18" W.C. draft pressure switch. Note: OEM part number HK06WC061 has been superseded by HK06MB061 — both are fulfilled as the current production replacement. Verify the W.C. rating on your unit's existing switch or data plate before ordering. Our fitment team is available to confirm compatibility before you buy.