Carrier HN67QC005 Sequencer Els PW 17895 whether installed inline or directly whether installed inline or directly at the pneumatic controller or actuator to prevent hunting and stabilize system output Industry best practices dictate replacing the gasket every time the heat exchanger cover plate is removed for cleaning or inspection The Carrier HN67QC005 Sequencer is a critical OEM replacement part designed to manage the staging of electric heating elements and blower motor operation in high efficiency electric furnaces and heat pump systems always verify the specific wiring diagram and pole configuration in your unit to ensure it matches the sequence requirements of your heater bank