OEM Carrier Draft Inducer Pressure Switch 0.18" WC for Model PY3GNA036090AA

This is the OEM factory-specified draft pressure switch for the Carrier PY3GNA036090AA packaged unit. The pressure switch monitors negative pressure created by the induced draft blower and proves that the flue path is clear before allowing ignition to proceed. When this switch fails or sticks open, the furnace or packaged unit will lock out on a fault code before ever attempting ignition — a classic symptom of a pressure switch failure. It can also fail intermittently due to a cracked rubber diaphragm, blocked pressure port, or waterlogged hose.

• Specs: 0.18" WC (water column) set point | Normally open | Single-port | Factory-matched Honeywell-sourced switch | Replaces OEM part numbers HK06WC061 and HK06MB061 (current superseding part)
• OEM vs Generic: This OEM switch is calibrated to the exact 0.18" WC trip point required by your unit's gas valve interlock sequence. Generic aftermarket switches frequently drift off-spec, triggering nuisance lockouts or — more dangerously — allowing ignition attempts in a blocked-flue condition.
• Install difficulty: 2/5 — Power down and tag out the unit before beginning. Tools needed: 1/4" nut driver, needle-nose pliers, and a manometer or U-tube if verifying trip point. Photograph the hose routing before removal. A cracked hose or blocked port is often the root cause — inspect both before condemning the switch.
• Warranty: 1-year OEM factory warranty against defects. In-stock and ships same business day from our warehouse.

Compatibility: Directly fits Carrier model PY3GNA036090AA. Also crosses to Bryant and Payne models sharing the HK06WC061 / HK06MB061 specification. Always confirm the 0.18" WC rating on your unit's wiring diagram or existing switch label before ordering. Have a fitment question? Our HVAC parts specialists verify compatibility before you buy — contact us today.