Trane BRD3456 Circuit Board 320788-702 the 60L27 features a 3/8"

the 60L27 features a 3/8" ODF inlet and a 1/2" ODF outlet

this low pressure switch 0

look for cracked insulation or corrosion at the spark plug terminal which causes high-voltage arcing to the boiler chassis instead of the electrode

ensuring the system operates only when the outdoor air is within a compatible range for the heat exchanger or cooling coil

37C73U-168 is the cross 110-202

Trane BRD3456 Circuit Board 320788-702 the 60L27 features a 3/8"The Trane BRD3456 Circuit Board is a critical OEM replacement HVAC control board engineered for high performance communication and logic sequencing within residential and commercial Trane systems. As a genuine system control motherboard, this unit manages the complex interactions between the thermostat, blower motor, and compressor, ensuring tight tolerances for operational timing and safety limit integration. Replacing a faulty or corroded board with