The automatic ball checks are a standard safety feature in the 24-300 series

Maintaining the correct combustion air flow is essential for preventing premature heat exchanger fatigue and ensuring stable pilot and burner ignition throughout the heating cycle

What happens if a crankcase heater is not replaced

though confirming the Carrier part number against the unit’s service manual is recommended

This valve is designed for non-corrosive refrigerants

Nordyne 669852R TXV Refrigerant The automatic ball checks areMaintain peak evaporator efficiency and prevent liquid slugging with the Nordyne 669852R TXV. This precision 4 ton thermal expansion valve is a genuine OEM component engineered for high pressure R410A refrigerant systems. Rated at 048K capacity, this metering device regulates refrigerant flow by monitoring superheat, ensuring the evaporator coil is fully utilized across varying thermal loads. As a direct replacement TXV for compatible Nordyne, Miller,