What was found
DURING CLIMBOUT, A BURNING ODOR AND LIGHT HAZE PERMEATED THE CABIN. THE LT PACK VALVE WAS PEGGED FULL RT AND THE LT DUCT TEMPERATURE REACHED 120 DEGREES. FLIGHT CREW SWITCHED THE LT PACK TO MANUAL CONTROL AND ODOR DISSIPATED. FLIGHT RETURNED TO CMH AND ON DESCENT, THE BURNING ODOR RETURNED WITH LT DUCT TEMPERATURE AT 150 DEGREES. LANDING WAS UNEVENTFUL AND MAINTENANCE REPLACED THE TEMPERATURE CONTROLLER AND BOTH WATER SEPARATORS. ALSO, FOUND A LOOSE DUCT ON THE AFT SIDE OF THE WATER SEPARATOR. ALL CHECKS WERE GOOD AND THE AIRCRAFT RETURNED TO SERVICE.