Our AC has been running constantly for the past 3 weeks (it is very hot and humid here), a couple of days ago water started coming out of the bottom of the furnace (it is a Lennox Whisper Heat), enough to have to change the towels every few hours. What could be the problem?

Clogged drain from condensate pan. Open unit up and clean the drain line to correct problem

OK Doug, we are not very handy. Can you please specify how to clean the drain line.
Thank you so much!

Cleaning the drain lines is easy. Out side the house, usually near the compressor unit, you will see a empty pipe coming out of the wall. Use a shop vac and drain the clogged water. While you drain the pipe, you here the noise inside the house near the furnace unit at the drainage.

I am draining the pipe almost every month. I live in south Florida where you need to use the AC unit most of the year. When I am using the AC unit, I am the only one draining the pipe while the rest of the 54 unit pipes are not leaking! I don't know, why only my furnace is leaking and what is the remedy. Service America technician came and did the same thing but, gave no remedy. Any suggestions please, how to fix this water leakage problem by which our carpet in the hallway is also gets moist frequently!
Much appreciated ahead for your valuable suggestions..