As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
F/A'S REPORTED EXCESSIVELY WARM AIR COMING FROM VENTS OVER ROWS 11-15. ATTEMPTED TO CONTROL FROM COCKPIT AND WAS INEFFECTIVE. ACFT GROUNDED. REMOVED & INSTALLED, TEMP CONTROL SENSOR FILTERS IN CONTROL CABIN, FWD & AFT CABIN. OPS CK. GOOD IN COOL & WARM MODES, REF 21-61-06 & AMM 36-00-00.