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LarryJ-nova 07-09-2013 02:52 PM

Condensation all over floor at furnace
Hi. I'm a townhouse owner in humid northern virginia with a carrier weathermaker 9200 gas furace that was installed about 6 years ago. It replaced an electric heat pump. The a/c part of the heat pump is still operational and used to cool the house. About 3 weeks ago I noticed a puddle of water coming from under the furnace. After changing the filter, the puddle didn't return until today. After changing the air filter and mop up today I noticed a dripping sound coming from inside the furnace. I checked the 3/4-inch pvc condensation drain and it's working fine (unlike a year or two ago when it was found to be plugged up). I'm stumped as to where this condensation dripping/build-up is coming from or how to prevent it. I'm not familiar with furnaces per se, but I do have a manual, so please use laymans terms in your replies. thanks for any help.

raylo32 07-09-2013 04:24 PM

It sounds like your evaporator coil drain pan might have hole or leak. You say the PVC drain line is clear but you might want to check where it enters the coil housing to make sure it isn't plugged there causing the drain pan to overflow. Also, was it raining hard when this happened? Reason I ask is because if you have an 80% furnace that is vented through the roof, you can have a problem with the rain cap or vent pipe that lets rain down into the furnace, hence onto the floor.

LarryJ-nova 07-09-2013 04:53 PM

I looked closer. The air filter access is in the intake air duct work about 8 inches from the unit. The drip was observed running along a duct work seam inside the supply air duct between the air filter and unit. There is little condensate exiting the condensate drain.

I don't know where the evaporator coil drain pan is located. All I've ever done is remove the front panel of the unit. I also removed the front panel on the top part of the unit which allowed me to see up the exhaust air duct and some coils.

We have had a lot of rain lately, but all the piping is horizontal leading out the back of the house.

raylo32 07-09-2013 05:56 PM

Probably help if you can post some pics. Others will chime in for sure....

Red Squirrel 07-09-2013 06:48 PM

Check the hose inside that feeds the cpvc pipe. I had a similar problem with my furnace and turned out I just had to tighten it with a hose clamp where it transitions from rubber to cpvc.

LarryJ-nova 07-09-2013 07:38 PM

here's a link to some pics

The coil drain pan (?) in the top part of the unit is mostly dry. Not overflowing. Nothings plugged. I couldn't see any holes, but it it corroded. Unit was installed in 2001.

There's water seeping out from the back of the lower unit into the front area where the black fan is located. Everything's still working though.

LarryJ-nova 07-09-2013 07:40 PM
here's 4 pics

raylo32 07-10-2013 05:13 AM

Larry, I live in the MD burbs... lovely humidity around here, too! Your water could be from several sources, condensation or rain. Referring to the pics tells us where exactly you are seeing signs of the water.

Also, it is easier for folks to view pics here in the forum instead of having to visit external sites. For PhotoBucket just go to your album, then click on the picture, then click on the <img> code to copy, then paste that inline in a forum message like this:

LarryJ-nova 07-10-2013 06:47 AM


The water is seeping out from the back half of the unit behind the divide just behind the black blower. I took a close up of it, but it didn't turn out well. I'm not authorized to paste attachements. to

The staining that is seen in the pic above is not water, it's oily stain. The dripping is inside the air duct to the left of the unit just right of the aluminum tape.

There is no overflow from the coil pan which is out of picture above the unit. And little water dripping from the condensate drain.

I don't know how rain water would enter this unit. The only piping (intake and exhaust for furnace) leading outside is run horizontally to the back of the house. And the dripping occurred when it was not raining for some time.

raylo32 07-10-2013 07:52 AM

You don't have to post attachments, you simply cut and paste the <img> code for each pic you want to post from PhotoBucket's sharing selections.

I can't tell what the soruce is from here. Maybe some of the pros will eventually chime in. One possibility is the air intake pipe, especially if it is a long run in conditioned space. Humid outside air will seep into the pipe, and the pipe is cold from being in conditioned space, and you can get condensate forming inside. This will run back to your furnace. The furnace manuals that I have seen recommend that a drain be placed in this line to capture and drain off any such condensate (or rain that might get into this pipe). I have seen many installs that do not have such a drain but I put one in mine when I installed my furnace.

But the obvious and most common thing would be a leak or overflow from the evap coil. But you say the line isn't clogged... <scratching head>.

LarryJ-nova 07-10-2013 07:53 AM<a href="...psbd7ba3f5.jpg[/IMG]

raylo32 07-10-2013 07:57 AM

Got to photobucket, click on the individual pic, then there will be 4 boxes to the right, one labeled img code. Just do one left click in that box and it will automatically copy it to the clipboard. Then just right click in a DIY Forum message and paste.

LarryJ-nova 07-10-2013 08:17 AM

LarryJ-nova 07-10-2013 08:19 AM

I poured water into the condensate drain pan above the unit. All of the water drained properly through the pvc drain. No dripping heard with water in the pan.
The water is seeping out from the back half of the unit behind the divide just behind the black blower.

LarryJ-nova 07-10-2013 05:04 PM

anyone have a suggestion?

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