My furnace appears to be leaking. What could it be?

Question

The bottom of my furnace has a lot of water and it's leaked on the surrounding areas.

Here are some pictures of it:

http://img521.imageshack.us/slideshow/player.php?id=img521/7866/12157295092yv.smil

In one of the images I show that it's not the tubes because they're not clogged and they're completely dry.

Answer 1

The pan that catches the water under your evaporator coils is plugged up, or the drain is plugged up.  Or the pan is rusted out.

Those sit ABOVE the furnace. Since the water is dripping clear through the furnace you are risking rusting out the furnace as well. It is not good and you need to fix it.

Are your filters clean? The coils could be freezing up it those are plugged up too.

Answer 2

This might be a case of a piece of duct work that didnt get insulated ,and is now collecting water by means of condensation.

Answer 3

The condensate is going to the bottom of the furnace instead of out the drain tubes to the condensate pump.  Check the dry lines for blockage.

Answer 4

Assuming you have A/C the water is condensation from the cooling coil  in the plenum. The drain for that must be plugged. You have to look above the furnace where the plenum is. Good Luck