As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SAW A SMALL PUFF OF SMOKE WHEN THE HEATER WAS TURNED OFF. THE FOLLOWING MORNING A FUNCTION TEST OF THE HEATER WAS PERFORMED AND A SMALL FIRE BROKE OUT. UPON INSPECTION IT WAS DETERMINED THAT THE INSULATION ON THE HEATER WIRES WAS CHAFFED AND SHORTED OUT. THIS MELTED A HOLE IN THE HEATER FUEL SUPPLY LINE. DAMAGE WAS CONFINED TO APPROXIMATELY 10 WIRES AND THE ALUMINUM FUEL LINE.