I have a Lenex unit and the drain has been leaking for a few days now and i cant figure out why.....I took the hose off the "T" and stuck a metal rod down there to see it anything was blocking it up and then after that i poored bleach down there to see if that would work but no luck....And it looks like the water is driping off the evaporator or somewhere in there cause there is a puddle on the furance...
it could be ice forming on the coil from:
a. low airflow (dirty filter, dirty coil, dirty blower wheel, etc...)
b. low refrigerant charge
or the coil pan may just be cracked or rusted through if metal.
when was the last time your system was serviced, sounds like its time.
Last time it was serviced the tech came out for the same reason and he said that he just cleaned 2 hoses unless he cleaned more then that i really dont know but thanks for your help
what is coil model number
Check your inside coil to see if it's dirty.
As said check blower wheel.
Also, try sucking the drain hose using a wet vac.
Are you getting good air flow coming from your registers and do the registers appear to be black and dirty on the outside of them, if so could very well be your blower wheel and/or "A" coil are filty.
if it is a downflow airhandler the coil on the cb29 and cb 30 models have to be flipped upside down....
when this is done lennox provides to metal drip shields that have to be installed on the inside of the coil. inserted into the drain pan which will illiminate the condensation from being pulled off of the evap coil when system is running
also if your using 3m or electrostatic filters that the system has not been designed for...take the out and replace with normal filter....