Preserve the condition
Do not reset the breaker, replace it with a larger one, open compartments, or touch suspected damaged wiring. If the heater is not already isolated, request qualified direction; do not approach unsafe access.
Take photographs only from a safe position. Save the model, serial number, nameplate information, installation invoice, and what happened before the trip.
Tell the installer explicitly that wire burns may be present. Request a licensed electrician as well as qualified water-heater review.
Check the whole path
The residential electric guide 321249 requires disconnecting power before service and suitable electrical connections. Its instructions do not establish whether your damaged heater can be repaired. Manufacturer-hosted electric guide.
Have the electrician assess the circuit and damage against the actual heater's nameplate, wiring diagram, and current applicable requirements. Have the equipment provider assess affected controls, elements, insulation, and other relevant parts.
Ask whether the mark is confirmed heat damage, where it originated, and whether surrounding parts are affected. A photograph alone cannot establish that.
Require a cause-based correction
If a connection, circuit mismatch, or equipment fault is found, request its correction and the necessary damaged-part scope. Manufacturer direction may be needed to establish repairability.
A new heater or breaker alone is not a complete solution unless it addresses the supported cause.
Ask how the providers will verify appropriate heating and electrical operation before return to use. Keep the written findings and repair record.
Resolve ownership and coverage
Separate installation correction, equipment coverage, and electrical work. Request who performs each part, what is included, and what requires authorization.
Your next step is to report the trip and possible burn marks to the installer and arrange coordinated qualified inspection. Keep the heater off until the damage and its cause have been resolved.