OEM Carrier Draft Pressure Switch 0.18" W.C. for Model PY4GEAA42090AA

This is the factory-specified OEM draft inducer pressure switch for the Carrier PY4GEAA42090AA packaged unit. The pressure switch monitors the negative pressure created by the inducer motor to confirm adequate combustion airflow before the control board allows the ignition sequence to proceed. When this switch fails or the sensing hose cracks, the furnace will lock out prior to ignition — often displaying a pressure switch fault code — leaving you with no heat. Replacing this switch with the correct OEM part restores precise 0.18" W.C. trip-point accuracy and reliable cold-weather starts.

• Specs: 0.18" W.C. (water column) set point | Single-port draft proving switch | Honeywell-manufactured (OEM cross: IS20224-5236) | Replaces HK06WC061 and current successor part HK06MB061
• OEM vs Generic: OEM switches are calibrated to exact factory W.C. tolerances. Off-brand switches with loose tolerances can cause nuisance lockouts in cold weather or, worse, allow ignition under unsafe draft conditions.
• Install difficulty: 2/5 — Turn off power and gas before servicing. Tools needed: 1/4" nut driver, flathead screwdriver, and a manometer to verify inducer pressure post-install. Disconnect the sensing hose and wiring harness, swap the switch, and reconnect. Always inspect the rubber sensing hose for cracks while the panel is open.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Confirmed fit for Carrier model PY4GEAA42090AA. Note that OEM part number HK06WC061 has been superseded by HK06MB061 — both are included in this listing and are direct functional replacements at the same 0.18" W.C. rating. Verify the W.C. rating on your existing switch label before ordering. Our fitment team is available to confirm compatibility before you buy.