Responded to call for Lennox NG furnace (6 years old) that was shutting down intermittently. Customer reported unit would run for extended periods then cease operation, with operation restored after blower door removal. Diagnosed and removed shipping bolt still attached to blower housing, which was causing operational issues. Applied dielectric grease to motor module connections to prevent future connectivity problems. Tested unit through multiple on/off cycles to confirm proper operation. Unit now functioning normally.
