Confirm the problem and the load
A failed component does not prove the whole system must be replaced, and the old nameplate does not prove the same capacity is still correct.
Document comfort complaints, repair history and any envelope changes before contractors size a replacement.
Compare complete installed scope
Require exact indoor and outdoor model numbers, the matched-system reference, duct findings, condensate work, electrical scope, permits and disposal.
A low quote may exclude duct sealing, platform work, line-set decisions, thermostat changes or permit fees.
Require startup evidence
Commissioning should verify airflow, refrigerant charge using the manufacturer procedure, electrical operation, drainage and controls.
Keep registration, parts warranty and labor warranty terms separate so the coverage can be compared accurately.
Sources and further reading
Questions or corrections? Contact the editorial team.



