OEM Carrier Pressure Switch HK02ZB038 for Model PY1PNA042120ACBA

This is the factory-specified OEM pressure switch for the Carrier PY1PNA042120ACBA packaged unit. The pressure switch proves that the inducer motor has created adequate draft before allowing the ignition sequence to proceed. When this switch fails or sticks open, the furnace will lock out before ignition — presenting as a no-heat call with the inducer running but no spark or gas flow. A failed pressure switch is one of the most common causes of a furnace fault code indicating "pressure switch open."

• Specs: Opens at 7" W.C. | Closes at 22" W.C. | 50" lead wires | OEM Part Number: HK02ZB038 | Also cross-references PS80-02-F0074
• OEM vs Generic: This is a genuine Carrier OEM switch calibrated to exact factory set-points. Aftermarket switches frequently carry ±5–10% W.C. tolerance, which can cause nuisance lockouts or — more dangerously — allow the unit to fire without adequate draft.
• Install difficulty: 2/5 — Disconnect power before servicing. Locate the switch on the inducer housing. Disconnect the rubber hose port and two wire leads, then swap and reconnect. Tools needed: flathead screwdriver, needle-nose pliers. Always inspect the hose and port for blockage or cracks before replacing the switch.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Direct OEM replacement for Carrier model PY1PNA042120ACBA packaged gas/electric units. Verify the W.C. rating on your existing switch label before ordering — if your existing switch reads different set-points, contact our team for fitment verification. Questions? Our HVAC parts specialists confirm compatibility before you buy.