Put the visits into one record
List the installation date, each freezing event, outside conditions, thermostat setting, filter used, and how long the system ran before failing. Add what each technician changed and whether that change helped. Include invoices and safe photos. Do not remove panels or repeatedly restart the system for evidence.
Ask the installer to identify the outdoor unit, indoor coil, furnace or air handler, and thermostat by full model number. The review should establish that these parts work together and that the settings and installation follow the instructions for that exact combination.
Request the original startup evidence
Ask for the installation's startup or commissioning record. Commissioning means checking that the installed system actually operates as intended. Useful evidence includes the method used to set and verify refrigerant charge, measured airflow, operating conditions during testing, and any installation issues found.
The next visit should compare current measurements with the equipment's specified requirements. Ask which finding explains the repeated ice and how the repair addresses it. If a leak is suspected, ask where it was found and what test supports that conclusion. If airflow is blamed, ask for the measurement and the cause of the restriction.
No single pressure reading or “it is cooling now” statement answers a fault that returns later.
Escalate with a clear request
Ask the installer's service manager to review the full record and provide a written repair plan, responsibility for each item, and a follow-up test. If the same explanation keeps changing without supporting evidence, an independent HVAC diagnosis can give you a clearer basis for the next decision.
Review installation workmanship coverage and the manufacturer warranty separately. Neither should be assumed to cover every visit or expense.
Your next step is to send the installer one concise timeline and request the matched-system, startup, and repeat-failure review. Keep cooling off during icing and arrange another cooled place if the home becomes uncomfortable or unsafe.