It is especially frustrating when the weather is blazing hot out there, yet you can’t stay cool indoor with your air conditioner. Sure enough you turned on the AC, checked the thermostat and hear the hoovering sound (yep, it’s blowing and should be working), but why is it still hot in here? You then place your hand over one of the AC registers and you discover your Air Cond is blowing warm air.
You wonder, what’s going on?! Am I able to fix the problem on my own, or do I need to call in the air cond service provider?
Fret not my friend, in this article you will learn about the most common cause of an AC blowing warm air. You’ll be surprised to know there might be some that you’re able to tackle yourself. 
4 Common Cause of AirCond Blowing Warm Air
1. Thermostat Issues
Among all and the simplest step is to check the thermostat. Sometimes things are not as bad as you imagine. Often the thermostat do get tampered with, by kids accidentally hitting it or tuned by someone else if they are too cold.
Just make sure the thermostat is set to COOL and the fan set to AUTO, as for the temperature it should be lower than the outdoor air. (eg: 24-26°C)
2. Clogged Filter
The AC filters are designed to remove dust & other contaminants from the air flowing through the equipment. However, a clogged filter may block air from entering the system. When that happens, the coil cant remove heat
If you haven’t had your AirCond serviced in a while, you should at least check your AC filter, and have it changed or cleaned.
3. Dirty Condenser Coil
The important function of your outdoor coil is to release heat outside of your building. As it exposes to other elements in the outer surrounding, it can be clotted with dirt & dust, not to mention leaves & trash.
In this case, you may flush & rinse the outdoor unit thoroughly. If the outdoor unit is not within your reach, you may hire a professional service provider to do the servicing for you.
4. Refrigerant leak
(To cut the explanation short) Refrigerant is the “special ingredient” that allows the magic of cooling work on your AC. You do not need to buy / refill them unless there’s a leak in your refrigerant line or coil.
When a leak occurs, your AC loses refrigerant charge and cooling power. Hence, it causes your Air Cond to blow warm air.
REMEMBER! Never allow anyone to add / refill more refrigerant without fixing the leak!
