As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN HEAT FWD/AFT/CABIN INOP CAME ON AFTER ENGINE START. AIRCRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE BITE CHECKED ZONE TEMP CONTROLLER IAW B767 21-61-00 NO MESSAGES PRESENT. ALL FAULTS ON EICAS CLEARED. A/C REMAINS ETOPS 180. AIRCRAFT RETURNED TO SERVICE.