As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, CREW NOTED UNCOMMANDED HOT AIR COMING INTO CABIN AND FLUCTUATIONS IN CABIN PRESSURIZATION RATE. RETURNED TO BASE, LANDING WAS UNEVENTFUL. COULD NOT DUPLICATE. AIRCRAFT RETURNED TO SERVICE. NO DISCREPANCIES ON RETURN FLIGHT.