As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE PILOT REPORTED A BURNING SMELL IN THE CABIN INFLIGHT WITH THE HEATER TURNED ON AND DISSIPATED WHEN THE HEATER WAS TURNED OFF. MAINTENANCE INSPECTED AND FOUND THE FUEL PUMP DRIVE BROKEN AND REPLACED THE HEATER FUEL PUMP WITH NO FURTHER DEFECTS NOTED.