13 - Common Central air conditioning issues – what and how to repair.
The condensate water line is clogged and floods everything below: The AC blower unit has what is called a “coil” where the humid air blows through and the water that collects is called the condensate water. This water then drops to a pan (that usually rusts badly) and then the water should flow into a pipe and take it to the outside of your house/building. When crud/dirt/whatever the filter didn’t catch ends up in this pan inevitably the water clogs up in the pipe that is never big enough to clear itself. Unless filters are changed regularly and you go a couple times a year and blow out this condensate line there will be trouble…one of two things happen:
The AC will automatically shut off if installed to code because it senses an overflow about to happen.
The pan overflows like Niagara Falls and shows up when you see water coming through the ceiling.
The solution to avoid this? Clean filters regularly (so the coils don't get covered in dust and debris), and have someone blow out the condensation drain lines at least once a year, like in the spring.
Thermostat goes bad: the way you know is the blower and outside units keep running, and the thermostat goes crazy…with the temperature showing all kinds of degrees.
The capacitor goes bad. This looks like a small can of soda. When there is a surge from the utility company/ lightening in an area this can happen.this capacitor burns out so your outside unit doesn’t blow up. Then what happens is the AC fan on the inside will still be blowing, but blowing hot air whilst the condensor (outside unit) will not be running, but you will hear a humming sound. If there are no cute little tropical birds around, most likely it will be that capacitor/little can of soda looking can gone bad. It is usually located on one corner of the condensor when you open up the side with a few screws.
No cooling and the outside unit is still running - This could possibly mean the AC system is low on Freon. Low on Freon translates to there is a leak. If there is a leak it is probably at either end of the lines where stuff shakes/vibrates, at the condenser outside or the blower inside or in the coils located in the blower. For older units more than ten years old, the coils on the inside blower unit tend to get corroded and then leak. You can't really fix that problem. If that is the case, replace the coils altogether as a minimum, and install a new drain pan while you are at it.