As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, PLANE DID NOT PRESSURIZE ON CLIMBOUT. RETURNED TO THE FIELD AND ACCOMPLISHED A UNEVENTFUL LANDING. INSPECTED DOOR SEALS AND FOUND AFT SERVICED DOOR SEAL FULL OF FROZEN WATER. REMOVED ICE AND DRIED ADEQUATELY. PERFORMED CHECK OF PRESSURIZATION IAW AMM FUNCTIONAL CHECK 21-31-00. NO DEFECTS NOTED. NO FAULTS IN CDS. RETURNED TO SERVICE. NO PARTS REPLACED.