Upon arrival the float switch was tripped in secondary pan.i opened up csbinet and it was full of water. I found build up of rust and sludge in pan blocking float and drain. I found downspout tube full of the same causing blowoff of coil. I vacuumed all the water I could from plenums and airhandler. It kept dripping waterfront under cabinet. I found 2 screws holes in bottom of cabinet. Water that I could not reach kept dripping and filling secondary pan enough to trip float. I finally got water removed and all slime removed from pan and drainline. It is cooling and draining at this time. I told homeowner to run fan to dry out plenums and cabinet.