I Need HVAC Help

[Dennis McDonaugh]

Kathy noticed a dark spot on the ceiling of the guest room this morning. I checked it out and it was definitely caused by water. The HVAC unit is right above the spot and its a little hard to see the ceiling from the top side because directly above the stain is an OSB floor for the HVAC unit and the hot water heater. The hot water heater is definitely not the source of the water nor does it appear the water is coming from the roof above. The water drain pan under the AC unit hasn't been wet. I think the water is leaking out the condensation line that leads to the sink in the bath next to the guest room. I'm not sure that it's actually leaking out of the PVC pipe however. It was wrapped in that black rubber pipe insulation and there was water between the pipe and the insulation. I pulled the insulation off for several feet and there was a dark stain on the OSB under the pipe. I've never seen one of these lines insulated before. Could it be condensation being trapped between the pipe and insulation instead of an actual leak in the pipe?

[Myk Rian]

Ever look at the end of one of those condensate lines? Green slime often accumulates in them.
Run a wire coat hanger up it. If it's plugged, the water is backing up and running over the condensate pan.

[Dennis McDonaugh]

Its clear, I dump bleach down it a couple times in the summer and I've blown air through the line. The pan is bone dry and never had water in it. I've pulled the sheet rock and insulation so the space is drying out. Once it's dry I'll clean it, put the insulation back and seal up the sheet rock. I'm going to replace the line from the AC unit to the far side of the attic, but I'm not going to re-insulate it.

[Kent Adams]

Kathy noticed a dark spot on the ceiling of the guest room this morning. I checked it out and it was definitely caused by water. The HVAC unit is right above the spot and its a little hard to see the ceiling from the top side because directly above the stain is an OSB floor for the HVAC unit and the hot water heater. The hot water heater is definitely not the source of the water nor does it appear the water is coming from the roof above. The water drain pan under the AC unit hasn't been wet. I think the water is leaking out the condensation line that leads to the sink in the bath next to the guest room. I'm not sure that it's actually leaking out of the PVC pipe however. It was wrapped in that black rubber pipe insulation and there was water between the pipe and the insulation. I pulled the insulation off for several feet and there was a dark stain on the OSB under the pipe. I've never seen one of these lines insulated before. Could it be condensation being trapped between the pipe and insulation instead of an actual leak in the pipe?

If it's not leaking along the pipe somewhere, then its leaking where the pipe connects to the condensate outlet. A slow drip from the connection will "ride" along the pipe until it's lowest point. Why would your condensate line even have insulation on it? It's not like you need to insulate it for the AC. It's simply a drip line.

[John Gomes]

Could be condensate dripping off the suction line while in ac mode. Check the insulation on the line. Those cold lines will drip like rain especially in humid areas

[Brad Adams]

I've repaired those before, sometimes the pvc pipe will have a hairline crack in it were the water seeps out.

[Dennis McDonaugh]

I re-ran the drain and repaired the ceiling. I can't check it for leaks until spring gets here so I put plastic down under the ac unit in case I forget to check when I turn it on. Thanks for the help.

[Dennis McDonaugh]

Well, its rained again and now I can see it wasn't the condensate line leaking. Rain water is running down the vent pipe for the gas furnace. The pipe makes a 90 degree bend just over the condensate pipe and that's where the water is coming off the vent pipe. I felt all around the pipe and I think the water is coming down the inside of the vent. I know there is a cap on top of the vent so I could use some help for what to look for when I go up on the roof.

[Lee Schierer]

I would suspect that the roof boot is either the wrong size for the vent pipe or it has cracked from exposure to the elements. A trip to the roof will answer the question. if it is cracked or split I would recommend replacement rather than trying any type of caulking.

[Dennis McDonaugh]

Lee, do I call a roofer or HVAC guy?

[Scott Shepherd]

Lee, do I call a roofer or HVAC guy?

You would call a roofer.

[Dennis McDonaugh]

Thanks Scott. It started raining hard again and I got in the attic with a flash light and can see water seeping in between the vent pipe and boot. It's not much, but it's there.

[Lee Schierer]

Thanks Scott. It started raining hard again and I got in the attic with a flash light and can see water seeping in between the vent pipe and boot. It's not much, but it's there.

In a pinch a hose clamp to fit the pipe and a sheet of plastic wrapped around the pipe on the roof side will buy you a few days or so.