As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED FRONT COMBUSTION HEATER INOPERATIVE. IT WAS DISCOVERED THAT THE HEATER CONBUSTION CAN HAD A HOLE IN THE REAR OF THE CAN, AFT OF THE EXHAUST. UNIT WAS REMOVED FROM SERVICE. IT IS SUSPECT THAT IMPROPER COOL DOWN PROCEDURES LED TO PREMATURE CAN FAILURE.