Order before 3PM CST — ships same day.
Standard delivery 2-5 business days. Express options at checkout.
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
These OEM pressure switches — HK02ZA395 (High Pressure Switch) and HK02ZB028 (Low Pressure Switch) — are the factory-specified replacements for the Payne PA4RNG024000BAAA air handler or packaged unit. Pressure switches prove that the inducer motor is creating adequate airflow through the heat exchanger before allowing ignition to proceed. When either switch fails, the control board interprets it as a venting or airflow fault and locks out the heating sequence entirely — leaving you with a system that attempts to start but never reaches ignition.
Compatibility: Designed specifically for the Payne PA4RNG024000BAAA. Verify which switch — high or low — you are replacing by checking your existing part number stamped on the switch body before ordering. Both switches are listed here for convenience; order the one matching your failed component. Need help confirming fitment? Our HVAC parts specialists verify compatibility before you buy — reach out before placing your order.