As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED FUMES IN AFT CABIN DURING FLIGHT. AT FL 220. THE AIRCRAFT WAS GROUNDED. TROUBLESHOT AND FOUND THE NR 1 ENGINE FUEL HEATER SERVO LEAKING. REPLACED FUEL HEATER SERVO IAW AMM 73-11-07. LEAK CHECKED GOOD, PACK RUN GOOD. NO FUMES OF FUEL IN CABIN. OK FOR SERVICE.