Weak airflow at supply registers

All HVAC symptoms

Clogged filter or blocked return

low

CheckPull filter. Measure return static with manometer (target <0.25" wc on residential).

FixReplace filter, open returns, add return drop if chronically high static.

ToolsManometer

Dirty blower wheel

med

CheckInspect squirrel-cage blades — dust caking reduces CFM dramatically.

FixPull blower, clean wheel with degreaser and brush.

ECM motor module fault

med

CheckVariable-speed ECM: stat call, no ramp. Check 24 V signal at motor harness.

FixReplace motor module (separate from rotor on most Genteq ECMs).

Safety

Pull the disconnect and lock out before opening HVAC equipment. Discharge dual-run capacitors before handling. Refrigerant recovery and brazing require EPA 608 certification and proper PPE.