As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED, CABIN HEATER INOPERATIVE DURING FLIGHT. 20 MINUTES PRIOR TO REACHING FINAL DESTINATION, CREW REPORTED ODOR OF SOMETHING MELTING OR SMOLDERING. HEATER WAS TURNED OFF, AND HEATER FUEL SOURCE WAS TURNED OFF ALSO. AFTER A FEW MINUTES, ODOR WENT AWAY. LANDING WAS UNEVENTFUL MX INSPECTED HEATER AND FOUND HEATER IGNITION UNIT FAILED AND SHORTED. MX R & R HEATER IGNITION UNIT, SYS CHECKED NORMAL. ACFT RELEASED BACK TO SERVICE.