Does this unit require a specific power polarity

the Weil McLain 381-800-477 7-inch vent damper is the critical OEM component required to maintain proper draft and combustion efficiency

Key Benefits Optimized Combustion: Maintains the precise air-to-fuel ratio necessary for high-efficiency burner operation

fitting both 3/8-inch and 1/2-inch round or square shafts commonly found in commercial ductwork

it ensures precise electrical compatibility and mechanical fit for Carrier

Carrier HH18HV125 Limit Switch 323613-751 Does this unit require aWhen you are troubleshooting a furnace that is tripping on high limit, you need a reliable, exact match replacement like the Carrier HH18HV125 Limit Switch. This genuine OEM furnace limit switch is a 95 125F auto limit switch designed as a primary safety control for your HVAC system. It features a Single Pole Double Throw (SPDT) configuration and is rated for 5 FLA at 240 VAC. The switch is engineered to open the circuit on temperature rise at 125F