How to Troubleshoot a Split Air Conditioner
Make sure that the five-way indicator on the indoor unit is on if the air conditioner does not work at all. If it is not, press the On/Off button on the remote control. See whether the Timer indicator is switched on. If it is, wait until its scheduled time to turn on or cancel the timer.
Ensure that there are no obstacles between you and the indoor unit if the air conditioner will not work with the remote control. Also, verify that the remote has batteries and that they are charged. Remember that you must be no more than seven yards from the unit in order for the remote to work.
Check that the correct operating mode has been selected if the air conditioner does not cool or heat. If this does not solve your problem, see if the room temperature is too hot or too cold. You may need to clean the air filter guard of dust.
See that the required temperature has been set correctly if, when heating, the desired room temperature is never reached or, when using the AC, the unit frequently stops. If it is set correctly, then increase the fan speed. Use the remote control to direct the air flow upward if it is directed downward.
Make sure that the operating mode is set to Cool, Heat or Fan if the fan speed does not change when you press the Fan button. If the unit is in Auto mode, the fan speed will change automatically, and in the Dry mode, it is set to Auto.