As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) HEATER UNIT OBTAINED AS REPLACEMENT ITEM AND ON FIRST FLIGHT THE PILOTS COMPLAINED THAT THEY WERE NOT ABLE TO CONTROL HEATER. INVESTIGATION REVEALED THAT THE FUEL SOLENOID VALVE SEAL WAS NOT INSTALLED PROPERLY AND THIS ALLOWED FUEL TO LEAK OUT OF THE COMBUSTION CHAMBER AND WHEN THE VENT PORT WAS PLUGGED, THE FUEL CAME OUT OF THE HEATER EXHAUST. SEAL REPLACED.