This Zonefirst AOBD series component is engineered for longevity in high-static applications where a standard HVAC zone damper might fail

Standardized Fitment: The 3/4" NPT connections allow for straightforward integration into existing headers and water heater ports

Broad Compatibility: Serves as a direct replacement for legacy models including 375-3/4-75 and LF174A-3/4-75

allowing for versatile configuration in both dehumidification and humidification sequences

and gas valve with automated timing

Carrier HK42FZ025 Control Board 318172-701 This Zonefirst AOBD series componentMaintain the operational integrity of your residential heating equipment with the Carrier HK42FZ025 Ignition Control Board. This genuine OEM furnace control board is a direct replacement designed specifically for Carrier, Bryant, and Payne units to manage critical ignition sequences, gas valve timing, and blower motor cycles. Engineered for precision, the HK42FZ025 utilizes advanced 24 VAC circuitry to monitor safety sensors and provide diagnostic