As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON GROUND WITH APU RUNNING, A FOOT LONG ORANGE FLAME WAS OBSERVED EMANATING FROM VENT ON COPILOTS SIDE ON BELLY. REMOVED ACCESS PANEL OVER DRAIN ASSY. REMOVED OLD ELEMENT AND INSPECTED AREA. INSTALLED A NEW HEATER ELEMENT AND GROMMET. APPLIED EA9396 TO HEATER ELEMENT WAITED FOR CURE TIME. OPERATED HEATER, OPS CHECK WAS GOOD. ALL WORK DONE IAW CH 38-30-02 OF THE MM.