As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
F/A REPORTED VERY HOT CABIN ENROUTE, SUPPLY DUCT TEMPS SHOWING 0 DEG C & CABIN TEMP SHOWED 12-14 DEG C. ACFT GROUNDED. AFT CABIN SENSOR WOULD NOT HOLD PAPER. VERIFIED FILTER CLOGGED & RESTRICTING AIRFLOW. CLEANED ALL 3 FILTERS IN A/C (2 CABIN & 1 FLT DECK) VERIFIED ALL FANS WORKING & AIRFLOW TEST GOOD. RAN TEMP THROUGHOUT & VERIFIED OPS TEST GOOD. GROUND VERIFICATION GOOD. REF B737-900 FIM 21-61 TASK 863.