As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CREW WAS TROUBLESHOOTING A CABIN TEMPERATURE PROBLEM THE CABIN BEGAN TO CLIMB UNCONTROLLABLY. THE CREW INITIATED AN EMERGENCY DESCENT, MANUALLY DROPPED THE OXY MASKS, AND MADE AN UNSCHEDULED LANDING AT JFK. FOUND RT PACK RAM AIR COUPLING TO HEAT EXCHANGER AND RUBBER COUPLING FOR INLET WATER SEPARATOR ASSY WERE BOTH BAD. REPLACED COUPLING P/N 5956186-501. CHECK-C 2-23-01 STL.