OEM Carrier High Pressure Switch HK02ZA442 for Model FIOP300B511GA

This OEM high pressure switch (part number HK02ZA442) is the factory-specified replacement for the Carrier FIOP300B511GA system. The pressure switch monitors the negative pressure created by the inducer draft motor to confirm proper venting before allowing the ignition sequence to proceed. When it fails or sticks open, the control board will lock out the system — preventing ignition entirely and typically triggering a fault code related to pressure switch failure. Common symptoms include the inducer motor running continuously with no ignition, or the system cycling off before the burners ever light.

• Specs: High pressure switch | OEM part number HK02ZA442 | Factory-calibrated W.C. (water column) rating | Single-port design | Matches original factory switching threshold exactly
• OEM vs Generic: This is a genuine OEM Carrier pressure switch, calibrated to the precise water-column rating required by the FIOP300B511GA. Aftermarket switches often carry wider switching tolerances, which can cause nuisance lockouts or — more dangerously — fail to detect a blocked flue, creating a potential safety hazard.
• Install Difficulty: 2/5 — Disconnect power before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers. Disconnect the rubber hose port and two-wire harness, swap the switch, and verify hose condition for cracks or blockages before reassembly. Check for fault codes to confirm repair.
• Warranty: 1-year OEM factory warranty against defects. Orders placed before cutoff ship the same business day from our warehouse.

Compatibility: Designed for the Carrier FIOP300B511GA packaged or air handler unit. Always verify your existing switch's W.C. rating and port configuration against your unit's data plate and wiring diagram before ordering to ensure a correct fit. Our parts specialists are available to confirm compatibility before you buy — don't guess on a safety-critical component. In stock and ships today.