Lots of Water Around HVAC Outside Unit

In early September of 2006 we experienced an air conditioning outage. (It’s still sweltering on Labor Day in Alabama). We had a coolant leak. I believe that the repairman replaced the evaporator. However, during this cooling season there is a lot of water (condensation) all around the pad. The unit has a small pvc pipe connected on the side where the condensation used to drip, but that pipe now stays bone-dry. The bottom of the unit and pad remain wet - mold has started growing around it. I clean up the mold and fungus but it comes back in about a week. I'm worried about rust damage to the unit due to the standing water. Is this a problem? What should I do?

The condensate drain is plugged and needs to be cleaned out. The thing is still wringing water out of the air, but instead of going down the drain, it is overflowing and coming out where you can see it now. Depends on how that line runs where and how you can clean it out. You might have to cut it and replace.

First place to look is the evaporator itself...underneath it is a pan with a hole for a drain that goes to the pvc pipe. See if it is clear there. You might be able to use a hose or an air compressor to try to clear the line, but you'd have to be there to evaluate whether that would be safe and would work.

Thanks Jim. My neighbor suggested just running a wire hanger up the pvc pipe (condensate drain?). Does this seem right? Is there a chance of causing major damage and/or receiving a electrical shock?

If this line terminates outside the house, and you have access to it, then get hold of a cannister snake and snake it out from there. If not, you'll have to use either a small snake or a cylinder of compressed air, N2, or CO2 from the inside.

Be careful if using compressed gas. Always hold onto the end of the hose when in use.

The pipe could be clogged anywhere, and without being there, we have no way to know how long it is, how many turns it has, or if you could mess something up by snaking it or poking with a wire. If a wire or snake made it all the way in to the actual evaporator coil and you poked hard enough, you could cut a line or smash the cooling fins. If it is a long ways away from the outlet and you stuck a coat hanger up with no chance of hitting that area, then yes, it is safe. There aren't any electrical components in the evaporator, but there could be a sensor on them. The bigger risk is poking a hole in the evaporator if you are doing that blind from the outside, not getting electrocuted.

Compressed gas from the outside would potentially splatter crud all over the inside of the unit...I wouldn't go there. The compressed gas could also shatter old, brittle pvc, so that's another reason to avoid that. From the inside to the outside, maybe. I had a similar problem and it ended up being a woody fungus growth. I was able to pull it out from the pan under the evaporator coils. I think you should start there, follow the pvc pipe to the outside. Depending on the unit, you can usually get access to the coils and the drain fairly easily, often by removing a single panel.

Whether for PM or because of a clog, In the thousands of condensation lines I've either snaked or blown out (mostly in large apartment complexes) never has a line or an evaporator become damaged. The worst thing that occurs is that you occasionally get drenched by a tidal wave of filthy water.

So, pick an end and get going.

PVC isn't rated for very much pressure, and after sitting in the sun, the uv damage can make it quite brittle. Use compressed air at your own risk.