OEM Carrier Draft Inducer Pressure Switch 0.18" WC for Model PY3GEAA42090NA

This is the OEM-specified draft pressure proving switch for the Carrier PY3GEAA42090NA packaged gas unit. The pressure switch monitors negative pressure created by the inducer motor to confirm safe venting before allowing ignition. When it fails or sticks open, the furnace control board cannot verify proper draft, causing the system to lock out on a pressure switch fault — typically before the igniter ever fires. Symptoms include a no-heat call with the inducer running continuously but ignition never advancing.

• Specs: 0.18" W.C. (water column) set point | Normally open | SPST configuration | Cross-references Honeywell IS20224-5236 | OEM part HK06WC061, superseded by HK06MB061
• OEM vs Generic: This OEM switch is factory-calibrated to the exact 0.18" W.C. trip point required by the PY3GEAA42090NA. Generic aftermarket switches often carry wider tolerances, which can cause nuisance lockouts or — more dangerously — allow ignition under marginal venting conditions.
• Install difficulty: 2/5 — Power down and lock out the unit before beginning. Tools needed: 1/4" nut driver, flathead screwdriver, and a manometer to verify draft post-install. Note tubing routing and terminal polarity before disconnecting the original switch.
• Warranty: 1-year OEM manufacturer warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed for the Carrier PY3GEAA42090NA packaged gas/electric unit. Note that OEM part number HK06WC061 has been superseded — current fulfillment ships as HK06MB061, a direct drop-in replacement with identical 0.18" W.C. specifications. Confirm your unit's existing switch rating on the data plate or existing switch body before ordering. Our fitment team is available to verify compatibility before you buy.