What is the problem if had your Trane central air for 5 years and you set thermostat at 70 degrees but when 90 outside temp 85 in house?

Possible causes:

- Dirty air filter.

- Blocked or dirty condenser coils.

- Refrigerant leak.

- Faulty thermostat.

- Undersized air conditioner.

- Leaking or poorly insulated ducts.

- Incorrectly calibrated thermostat.

- Insufficient airflow.

- Blocked or dirty evaporator coils.

- Faulty compressor.

- Faulty fan motor.

- Faulty control board.

- Incorrectly installed air conditioner.