OEM Carrier Draft Inducer Pressure Switch 0.18" WC for Model PY3GPAA36090AA

This OEM Carrier pressure switch (part number HK06WC061, superseded by HK06MB061) is the factory-specified replacement for the Carrier PY3GPAA36090AA packaged gas/electric unit. The pressure switch monitors negative pressure created by the draft inducer motor to prove that the flue vent is open and drawing properly before allowing ignition to proceed. When this switch fails, the control board cannot confirm safe venting conditions and will lock out the furnace — typically before the igniter ever glows. Common symptoms include a furnace that runs the inducer but never attempts ignition, an error code indicating a pressure switch fault, or a unit that short-cycles immediately at startup.

• Specs: 0.18" Water Column (WC) set point | SPST (Single Pole, Single Throw) | Draft inducer proving switch | Replaces Honeywell IS20224-5236 / 1638D2/B | OEM part cross-reference: HK06WC061 → HK06MB061
• OEM vs Generic: This is a factory-authorized OEM replacement, calibrated to the exact 0.18" WC trip point required by the PY3GPAA36090AA control board. Generic pressure switches are often rated at ±10–15% tolerance, which can cause nuisance lockouts or, worse, fail to detect true venting problems — a potential safety hazard on gas appliances.
• Install difficulty: 2/5 — Turn off power and gas before servicing. Locate the pressure switch on the inducer housing or cabinet wall. Disconnect the single hose port and two electrical terminals (photograph before disconnecting). Swap the switch, reconnect, and restore power. Tools needed: flathead screwdriver, needle-nose pliers. Verify error codes are cleared after installation.
• Warranty: 1-year OEM manufacturer warranty. In-stock units ship same business day when ordered by 5 PM ET.

Compatibility: Designed for the Carrier PY3GPAA36090AA packaged unit. Also fits select Bryant and Payne models sharing the same inducer and control board configuration — verify the 0.18" WC rating on your unit's data plate before ordering. Note: HK06WC061 has been superseded by HK06MB061; both part numbers are fulfilled with the current production unit. Our fitment team is available to confirm compatibility before you order.