- Installer: ask for site inspection and fault isolation under the workmanship/service contract.
- Manufacturer: open the product or performance claim with the required serials and test evidence.
- Inverter service network: use the device error code, logs and model-specific procedure.
- Insurer: use the policy notice route for a covered external event; preserve damaged parts if instructed.
Send one chronology with installation date, first symptom, data gap, inspections and requested remedy. Ask each party to state whether it accepts responsibility, which clause it relies on, what additional evidence it needs, who bears each incidental cost and the next response date. A vague “system is underperforming” ticket invites vague answers.