Inspect your unit and make sure it is on. Listen for the fan blower and make sure it is running.
Turn on your thermostat if it is off. Set it in the "Cool" position and adjust the temperature to your preference. Check the display for a low battery warning if it is not functioning. Open the battery compartment if you see this warning and remove the old batteries. Insert new batteries and turn on your thermostat.
Inspect your Carrier air conditioner's circuit breakers and make sure they are on. The circuit breakers are located on a wall next to your outdoor unit. If the circuit breakers are on, turn them off and then turn them back on. This resets them. If you are unable to locate your circuit breakers, refer to your unit's operating manual.
Check the disconnect switch in the electrical box near your outdoor unit. Make sure it is on. If it is on, turn it off and then turn it on again.
Remove the filter from your unit and inspect it. If it is dirty, remove dirt and debris. A blocked filter can limit the air flow. Instructions for cleaning filters vary by unit, so refer to your owner's manual. Inspect your filter for wear and tear. Replace it if it is damaged. If you do not have a replacement filter, purchase one from a hardware, retail or appliance store.
Check your Carrier air conditioner's air grills and make sure they are open to allow sufficient airflow. Air grills are usually located on your walls and are wide and flat. Remove any objects blocking air flow.
- Contact a qualified technician if your unit is still not working.