As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT FUEL TANK TEMP INDICATED +99°C WITH FIRE BELL. REMOVED AND REPLACED THE RT FUEL HEATER THERMAL ACTUATOR INAW DHC-8-400 AMM 73-11-05 (FOR THE FUEL OVERHEAT). SWAPPED INPUT/OUTPUT MODULE (IOM) POSITIONS IAW Q400 AMM 31-41-11 (FOR TROUBLE SHOOTING THE FIRE BELL SOUNDING).