This will probably be hard to diagnose without seeing the problem but I though I would run it by you guys since the HVAC tech wasn't sure what to do. I have a lennox heat pump with the furnace in our garage. It is an upflow unit so the filter is at the bottom of the unit with the coils and drip pan just above. About a month ago when I went to change the filter I noticed some water was dripping onto the filter. It wasn't a whole lot but enough to cause a little mold growth on the filter. I called the hvac tech and he thought it was the condensation drain line sweating and dripping onto the filter. He came out and wrapped more insulation around the pipe. I mentioned to him I didn't think that's what it was but he isisted it would fix the problem. Well, I check the filter last night and sure enough there was more water on it. I noticed there is some wrapping underneath the drip pan and when I pulled the wrapping down just a little water came out. It looks like water is builidng up between the wrapping and the drip pan. I don't think it would be a leak since the unit is only 2 years old and the pan is plastic. Could the pan just be sweating underneath? Has anyone ever seen anything like this. I just want to know what I can't tell the hvac tech to help him diagnose the problem. Thanks for the help.

Get the company back out there to do it right water shouldn't be coming into your furnase, make them do it right and the tech should know how to remady this... ask how long he's been doing this, and when calling a company ask how experienced the tech's are, Be sure to tell the phone contact the same problem still exist,, and you will not be paying additional monies, as you have already paid

Thanks for the reply. The hvac guys is still at a loss as to how to stop the water from dripping. Its just a small drip and its seems to be coming from the underside of the steel frame that holds the coils. It looks like underside of the frame is sweating and its dripping into the corner and settling between the padding and underside of the drip pan. The tech says its due the furnace being in the garage and the high humidity of the area.

Get a second opinion - it really shouldn't be leaking inside the unit. Make sure the drain line in completely clear - examine the drain pan carefully - make sure it is level. Plastic can develop cracks too. Check any and all connections to the drain pan. A little food coloring in the pan would likely let you know if that were the source.

We have been able to determine its definitely not a leak and the line is clear. It just seems to be sweating underneath for some reason. One explanation I was giving is that since the return air ducts runs through the garage that the return air warms up enough to cause condensation to develop a little on the galvanized steel holding the coils. Not sure if its accurate but it makes sense. I have had another hvac tech say the same thing. I may just need to insulate the return duct in the garage.