As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS BROUGHT INTO SHOP WITH THE HEATER INOPERATIVE. INSPECTION REVEALED A .500 INCH DIAMETER HOLE IN THE COMBUSTION HEAD JUST BELOW AND TO THE RIGHT OF THE IGNITOR, NEAR THE FUEL SUPPLY LINE. RECOMMEND VISUAL INSPECTION AND/OR PRESSURE TEST EACH 100 HOURS OF HEATER OPERATION.