This can happen for various reasons, the most common of which is that your unit was installed in the attic or on an upper floor, causing difficulties with the drain overflowing and dripping out the vent.
Examine your condenser unit, which is the large unit outside your home, to find the source of the problem.
You're probably dealing with a clogged condensate drain line if the drip pan is overflowing. Schedule your appointment with Traditional Services today for water leak detection in Tomball, TX.