One of the most common problems with an air conditioner is a water leak. If you notice water leaking from your air conditioning system, don’t panic. The first thing you need to do is turn the unit off. This is important because water can damage the wiring and the unit itself. Your next step should be to contact a local HVAC professional. The most common problems that will result in leaking water from the air conditioner include the following. 
Improperly Sealed Unit
An improperly sealed unit will leak water when warm outside air enters the unit and gets condensed by the cool air that’s generated by the unit. As the moisture builds up inside the unit, the water will eventually leak out. It is best to let a trained HVAC professional check the problem out and properly seal the unit.Refrigerant is Low
The pressure inside the air conditioning system will be low if the refrigerant level is low. The problem with this is that it will cause the evaporator coil to freeze. When the coil melts, this will cause water to overflow into the drip tray. So, it’s possible that if you see dripping water, it could mean that the refrigerant is low.Water Drain is Blocked
A build-up of dust and dirt can block the drain holes at the rear of the air conditioning system. When the drain holes are blocked it prevents moisture from escaping from the unit, and this will result in leaking water. A/C maintenance that includes regular cleaning of the unit can prevent this problem.Low Outside Temperatures
During the winter, when the temperatures drop drastically, water cannot evaporate as it would when temperatures are warmer. As a result of this, water builds up inside the unit and will leak out.
