This OEM Trane pressure switch acts as a fail-safe

the ST9120C4054 is primarily a timing-based fan control and should be used in conjunction with your ignition module's diagnostics to identify gas-side issues

it requires a specific run capacitor (typically 5 MFD/370V) which should be replaced at the same time as the motor to ensure peak performance

ensuring exact pitch and rotation

Direct OEM Compatibility: Verified Nordyne furnace part that serves as a drop-in replacement for M0108606R and M0108606

National Comfort Products 14265025 Door Switch 320734-701 This OEM Trane pressure switchThe National Comfort Products 14265025 Door Switch is a critical safety and operational component designed specifically for thru the wall condensing units and heating systems. As a veteran grade HVAC replacement part, this switch provides precise door position sensing, functioning as a high reliability interlock that prevents system operation when the access panel is removed. This OEM door switch ensures that high voltage blower components and burners