OEM Carrier Draft Inducer Pressure Switch 0.18" WC for Model PY4GEAB48090AA

This is the genuine OEM factory-specified draft inducer pressure switch for the Carrier PY4GEAB48090AA 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 and will lock out the unit — resulting in a no-heat call with an inducer that runs but no ignition spark or gas valve activity. The switch is rated at 0.18" water column (WC) and is a single-pole, single-throw (SPST) normally open design that closes on a rise in negative pressure.

• Specs: 0.18" WC set point | SPST normally open | Honeywell/Resideo OEM diaphragm | Cross-references: HK06WC061, HK06MB061, IS20224-5236
• OEM vs Generic: OEM switches are factory-calibrated to exact WC tolerances. Aftermarket units frequently drift ±0.05" WC or more, causing nuisance lockouts or — worse — failing to detect blocked flue conditions, creating a safety hazard.
• Install difficulty: 2/5 — Shut off power and gas before servicing. Tools needed: 1/4" nut driver, small flathead screwdriver, and a manometer or magnehelic gauge to verify set point after install. Photograph hose routing before disconnecting tubing. Inspect rubber hose for cracks while the panel is open.
• Warranty: 1-year OEM manufacturer warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Fits Carrier PY4GEAB48090AA packaged gas/electric units. OEM part number HK06WC061 has been superseded by HK06MB061 — both are the identical switch and are fully interchangeable. Verify the 0.18" WC rating on your unit's existing switch before ordering. Our fitment team is available to confirm compatibility before you purchase.