OEM Carrier Furnace Draft Pressure Switch 0.18" WC for Model PY3GNAA42090NA

This is the OEM-spec draft proving pressure switch for the Carrier PY3GNAA42090NA packaged gas/electric unit. The pressure switch monitors inducer motor operation by sensing negative air pressure in the flue passage. When the inducer creates sufficient draft, the switch closes and allows the control board to proceed with ignition. A failed pressure switch causes the furnace to lock out before the ignition sequence ever begins — often accompanied by a fault code indicating an open pressure switch. This part supersedes original OEM part number HK06WC061 and ships as the updated replacement HK06MB061, the current Carrier Factory Authorized Parts designation.

• Specs: 0.18" W.C. (inches water column) rating | Single-port draft proving switch | Honeywell-manufactured (IS20224-5236) | Normally open, closes on inducer draft
• OEM vs Generic: OEM pressure switches are calibrated to exact W.C. factory tolerances. Aftermarket units with off-spec setpoints can cause nuisance lockouts in cold weather or — worse — allow unsafe operation with inadequate flue draft. OEM is always the safer choice for pressure-proving components.
• Install difficulty: 2/5 — Shut off power and gas supply before servicing. Tools needed: 1/4" nut driver, flathead screwdriver, multimeter (continuity test). Disconnect the rubber hose from the inducer port, unplug the spade connectors, and swap the switch. Always verify continuity across the switch terminals with the inducer running before reassembly.
• Warranty: 1-year OEM factory warranty. In stock and ships same business day from our warehouse.

Compatibility: Engineered as the direct OEM replacement for Carrier model PY3GNAA42090NA. This switch also fits select Bryant and Payne packaged units sharing the same inducer assembly and 0.18" W.C. draft specification. Always verify the W.C. rating printed on your existing switch before ordering. Have a fitment question? Our HVAC parts specialists confirm compatibility before you buy — call or chat today.