OEM Carrier Low Pressure Switch HK02ZB028 for Model HA1AJX024000ABAA

This OEM low pressure switch (part number HK02ZB028) is the factory-specified replacement for the Carrier HA1AJX024000ABAA. The pressure switch is a critical safety component that monitors negative pressure created by the inducer draft motor to confirm proper venting before allowing the ignition sequence to proceed. When this switch fails or becomes stuck open, the furnace will lockout before ignition — leaving you with no heat and often a diagnostic fault code indicating a pressure switch fault.

• Specs: Low pressure switch | OEM part number HK02ZB028 | Factory-calibrated W.C. (water column) rating | Single-port design | 24V control circuit compatible
• OEM vs Generic: This OEM switch is calibrated to the exact water column rating required by the HA1AJX024000ABAA. Aftermarket switches frequently carry loose W.C. tolerances that can cause nuisance lockouts or — more dangerously — allow the furnace to fire under improper draft conditions.
• Install difficulty: 3/5 — Disconnect power and gas before servicing. Tools needed: flathead and Phillips screwdrivers, needle-nose pliers, multimeter (to confirm switch continuity). Inspect the inducer port and pressure tubing for cracks or blockages before installing the new switch, as a clogged hose is a common root cause of switch failure.
• Warranty: 1-year OEM factory warranty. In-stock and ships same business day from our warehouse.

Compatibility: Designed specifically for the Carrier HA1AJX024000ABAA. Always verify the W.C. rating printed on your existing switch and cross-reference OEM part number HK02ZB028 before ordering. If you have questions about fitment, our HVAC parts specialists verify compatibility before you buy — just reach out. Order today and get same-day shipping on all in-stock parts.