As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING REPLACEMENT OF THE FILL DRAIN VALVE FAOUND THE WATER HEATER VALVE TO BE DAMAGED AND THE INSULATION BURNT. INSTALLED NEW WATER HEATER FILL VALVE IAW E175 AMM 30-71-05-400-801-A AND REPAIRED INSULATION IAW E175 AMM 20-15-300-801-A. RETURNED TO SERVICE.