OEM Carrier Draft Pressure Switch 0.18" WC for Model PY3GNA024040AA

This OEM Carrier draft pressure proving switch (part HK06WC061 / superseded by HK06MB061) is the factory-specified replacement for the Carrier PY3GNA024040AA packaged unit. The pressure switch monitors negative pressure created by the inducer motor to confirm safe venting before allowing the gas valve to open. When it fails or sticks open, the furnace will lock out before ever reaching the ignition stage — leaving you with a blower that runs but no heat.

• Specs: 0.18" Water Column (WC) | Normally Open (N.O.) | Single-port diaphragm switch | Replaces Honeywell IS20224-5236 / 1639D2/B | Superseded part: HK06MB061
• OEM vs Generic: OEM pressure switches are calibrated to the exact factory setpoint. Generic equivalents often drift in WC rating over time, causing nuisance lockouts or — worse — unsafe ignition attempts. Always match the rated WC stamped on your original switch.
• Install Difficulty: 2/5 — No refrigerant or high-voltage work required. Tools needed: 1/4" hex driver, flathead screwdriver, and a short length of replacement tubing. Inspect the hose port and tubing for cracks or blockages before installing the new switch.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Engineered for the Carrier PY3GNA024040AA packaged unit. Also cross-compatible with select Bryant and Payne models using the 0.18" WC specification — verify the WC rating on your existing switch's label before ordering. Note: OEM part number HK06WC061 has been superseded by HK06MB061; both ratings and dimensions are identical. Questions about fitment? Our HVAC parts specialists verify compatibility before you order.