# HELP: Lennox C33-36C-2F leaking water



## hamproof (Jan 4, 2010)

Hi - I'm trying to troubleshoot this and can't figure out where the water is coming from.

Initially, when this first happened, I thought it was a clogged humidifier filter. I've since changed the filter and cleaned out the casing and it is still leaking. I've poured water into tube where the excess water from the humidifier will drain out too, and it clear. No blockage. It drains into the floor.

I've also poured water into the A-coil pan and that too seem to drain ok (but I cannot be 100% sure) but there seem to be residual water in there that dries out (if I don't use the humidifier) after a couple of days.

But each time I turn on the humidifier, it'll drip water. It drips onto the blower motor housing, and also on the outside where the air filter is. I guess it is seeping through the seams. I've removed the 2 panels covering the furnace, as well as looked through the cutout where the humidifier is mounted at the A-coil and drip pan, but I can't figure out where the leak is coming from.

On the right side of the furnace (airfilter is on the left), I see a plastic box that seem to collect water. At the bottom, there's small rubber cap. I've removed this and drain the water out as well. I've also poured water into the tube where this plastic box drains and there appears to be no clogs.

Where do I go from here? Thanks.

I've read this thread but I'm not sure which small black hose is mentioned there.

http://www.diychatroom.com/f17/help-lennox-elite-series-furnace-m-n-90ugfa3-75-5-a-59214/


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## yuri (Nov 29, 2008)

Post some pics of the humidifier and where it attaches to the furnace. That # is for a evaporator coil.


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## Marty S. (Oct 31, 2009)

If your humidifier has a plastic line inside to water the pad check that for cracks.


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## hamproof (Jan 4, 2010)

Thanks for the reply. I've left the humidifier cover off and watch the water flow from the top of casing to the top of the filter which eventually goes into the channels of the filter frame. So, there shouldn't be a drip there. I'll turn it on again and watch it to see if it ever overflows, but I doubt it since this is a new filter.

Any other ideas?


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## hamproof (Jan 4, 2010)

Here's the makeup of humidifier and HVAC. 

Photo 1: Humidifier with cover off. New filter just put in.

Photo 2: Drain lines

Photo 3: No blockage. Water just flows out from the outlet

Photo 4: No blockage here either. I pour water down the tube and it drains properly

Photo 5: Can see some water spots here. I don't think it is coming out from the tube with the white end cap. Rather, it is seeping through the bottom metal seams.

Photo 6: What it looks like inside (what's the 2 small black hose for??)

Other than the air filter area being wet (photo 5), the floor underneath is wet as well. But it is not coming from the left of the air filter area. I put a pan underneath the air filter area, and it is not accumulating any water. So, the water is coming from underneath the furnace area I suspect.

Also, the 2 black hoses in photo 6, the one further out just seem to vent out to. I can see where it comes out on the left side panel (in photo 5). The inner out, I cannot see where it is coming out as it is covered by the panel. I removed the inner one (the one that connects to the big black rubber tube) and some water drain out. Not sure the purpose of these 2 tubes and why one of the outlet is covered by the panel inside the casing by the airfilter.


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## hamproof (Jan 4, 2010)

This is the other side. 2 black hoses here as well. But at least this one connects to a black outer collection box. There's water in the box. I poured water into the white pvc piping and it drains properly as well. At the lower right side of the box, there's a rubber end cap which I can removed. When I remove it, water drains out.

Back to the left side where the 2 black hoses are, when I removed the inner one, I used a flex metal wire trying to push thru (gently) and see where it comes out on the airfilter side, but I cannot do it. It appears to be in penetrable and I didn't want to force it for fear it might rip something.

Similarly, on the outside, I try to use a flex metal wire to poke through, but can't either. So, water is never meant to exit from here??


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## beenthere (Oct 11, 2008)

The black troft that sits on top of the pad. Does it look like it has sand/grit in it?
If not. Then its not letting an equal amount of water flow across the pad, and is causing water to overflow the pad.


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## hamproof (Jan 4, 2010)

It did had a bunch. But I clean it up as much as I could. I wanted a buy a whole new casing including the fiter, but couldn't find one.

I'll try to clean it up even more and see if it solves the issue. I think I can even run the furnace and humidifier w/ the humidifier cover off and watch if any water flows out or not. I've watch it for about 5 mins before covering it up and it appears to be ok.

Thanks for the suggestion.


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## Marty S. (Oct 31, 2009)

Those black hoses are the drain lines for your furnace heat exchanger and the black box on the other side is a trap. Don't be poking wires in there! If you want to check them take the hose clamp off and blow through them. 

The first post indicated the water problem goes away when the humidifier is turned off. If that is correct then it's not a furnace condensate problem. You shouldn't get water in the coil drain pan from the humidifier. Pour a cup or two of bleach down the bottom of the humidifier to kill the slime mold that builds up in the drain line. I'd move the humidifier to the return so next time it backs up the water cant run inside the furnace costing you big $ for a motor and circuit board.


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## beenthere (Oct 11, 2008)

hamproof said:


> It did had a bunch. But I clean it up as much as I could. I wanted a buy a whole new casing including the fiter, but couldn't find one.


If you scraped if off. You need a new troft.

Also. Where does that drain run to? If its restricted. then with the humidifier going into the A/C drain line. The air pressure could be interfering with the water draining out of the humidifier.


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## hamproof (Jan 4, 2010)

beenthere -- I cleaned it by soaking in vinegar and using a toothbrush. In the second photo, you can see the humidifier drain pipe and the A-coil collector pan drain are connected as such and drain into the floor drain.

marty s -- In the first photo, the humidifier is mounted on the furnace side, but there's also a vent duct that connects it to the return side. Is this common? What's the purpose?

This was a new condo and we've lived here since 2004. Last Nov 2009 was when this issue started. Thanks.


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## beenthere (Oct 11, 2008)

That troft is NEVER suppose to be scrubbed clean.

Did you check the trap in the drain line for the A/C and humidifier.

Thats a bypass humidifier. The pipe that runs to the return is the bypass. Thats how air flows through it.


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## hamproof (Jan 4, 2010)

beenthere - I'll see if I can find another troft at a specialty store. By trap at the drain line, you mean the pvc piping that ends at the floor? In the 2nd photo, the pvc line for the humidifier and heater connects and terminates at the floor (into a drain hole).

Appreciate the help.


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## hamproof (Jan 4, 2010)

Darn, just read the Lennox WB2-17 manual online and realized what "beenthere" is saying. I guess those deposit which I thought were mineral deposit from the water, were part of the design. The Lennox manual did say it is ok to clean from the "V" channels which I did. But according to the manual, one can remedy the situation by putting a few drops of liquid soap in the tray.

http://www.ontimemall.com/manuals/lennoxWB2humid.pdf

I'll give that a try and see if it improves the situation while I look for a replacement.

Is there a way I can be certain this is the issue before buying the replacement part? I guess they call it a water distribution tray and it cost ~$27 shipped.


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## beenthere (Oct 11, 2008)

Pic 5 has shows the trap.

Probably have to order the troft from Aprailaire.


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## hamproof (Jan 4, 2010)

The big black rubber tubing that is capped at the end with the white piece? Do I just try to pry it off then? And how do I go about cleaning it?

Yes, I did order a Aprilaire replacement part. Local Lennox dealer wanted $42 for a Lennox part.


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## beenthere (Oct 11, 2008)

No. The PVC. It has a u shape in it.


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## hamproof (Jan 4, 2010)

I did pour water from where the humidifier drains and I didn't notice any water backing up. Granted I maybe did a 1/2liter of water and not a whole bucket. I'll try to pour more water and see if it drains properly into the drain.

But if I do need to clean it, how do I do it? I would rather not cut the pipe off. Just use CLR or something similar?


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## beenthere (Oct 11, 2008)

Probably have to cut pipe open. Since they didn't allow for it to be cleaned.


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## hamproof (Jan 4, 2010)

I got a replacement Aprilaire water collection part and installed it. Turn on the humidifier and within minutes it was apparent where the leak is. Previously, I had to wait about 1/2hr before any water sign shows up.

So, it turns out it is leaking at the PVC exhaust side going out the house (see attached photo).

Also, I had previously mentioned that it is also leaking through the seams and water gets collected on top of the air filter panel area.

Well, looking carefully this time, I believe it is leaking through the rubber tube that is capped at the end (white piece). This same rubber tube is connected to the PVC exhaust side which I mentioned is leaking as well.

What should I do next? Water is suppose to be collected into that little black box on the right side of the HVAC which then goes to the drain. Should I investigate more, or fix the PVC tubing first? How to fix the PVC? Use some epoxy? Or cut it out and replace? I believe the leak is from the joints between the PVC (curve elbow and straight).

Thanks.


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## beenthere (Oct 11, 2008)

If the humidifier is leaking through a 2" PVC furnace exhaust pipe. then something isn't piped right. And you got a restriction somewhere.

Post a wider angle pic of your piping. And mark which pipe is leaking. And which pipes come from where.

Also, I don't see a pipe clamp on teh one connection where it should be.


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## hamproof (Jan 4, 2010)

Sorry for the delay. Here are some new photos. The last photo shows where the leak is (arrow).

Shouldn't the water be collected on the black tube running vertical on the right side to the collection box on the outer right side?

Thanks.


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## beenthere (Oct 11, 2008)

Looks like the PVC is pushing down on the furnace exhaust(exhaust is supporting PVC).
It shouldn't. How is the PVC supported?


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## Marty S. (Oct 31, 2009)

You'll need to buy the black plastic part in the furnace that the PVC glues onto unless you have a pipe hog laying around the house. Humidifier doesn't have anything to do with that leak.


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## hamproof (Jan 4, 2010)

beenthere - I haven't had a chance to take a photo of how it is attached. I will tomorrow.

marty - The humidifier has not been for a few months now. So, no wetness. But whenever I attempt to fix it (new filter, new troth etc) and turn it on, within 10mins or so, there's water accumulation on the floor and the last time I tried this, I manage to see it dripping from where I indicated.

I think it is related to the humidifier.


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## Marty S. (Oct 31, 2009)

That is the exhaust pipe for your furnace. The humidifier isn't connected to it in any way. The water has to be traveling from the humidifier and dripping on the pipe then.


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## hamproof (Jan 4, 2010)

Is it possible the moisture from the humidifier causes excessive condensation due to the heat and this condensation/water is the cause of leak? Is the water from the exhaust going through the same pipe as the condensation water from the humidifier?

Not sure if I'm wording it right. But it seem to me as the water flows through the filter element, some of it gets evaporated and flows through the ducts but some of it will condensate and gets collected in the a-coil pan. But looking at how the piping is, the water from the a-coil pan should just go through the small PVC pipes and not the black tube. 

Maybe there's a crack in the a-coil pan or the water overflows from the pan. If so, where does this water go to?

Thanks


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## Marty S. (Oct 31, 2009)

hamproof said:


> Is it possible the moisture from the humidifier causes excessive condensation due to the heat and this condensation/water is the cause of leak? Is the water from the exhaust going through the same pipe as the condensation water from the humidifier?
> 
> Not sure if I'm wording it right. But it seem to me as the water flows through the filter element, some of it gets evaporated and flows through the ducts but some of it will condensate and gets collected in the a-coil pan. But looking at how the piping is, the water from the a-coil pan should just go through the small PVC pipes and not the black tube.
> 
> ...


 The hot air from the furnace evaporates water off of the humidifier pad, not condenses it. The exhause pipe water is seperated from the humidifier air by a steel heat exchanger so it can not come back through that way.

The way your coil and humidifier are piped a plugged line will make the water back up into the coil pan and with nowhere to go it will overflow onto the furnace. Should be no water in the coil pan unless the AC is running so if you have water there then the 3/4" pipe is plugged enough it cant keep up with the humidifier output. Cut the 3/4" lines and clean them out from one end to the other.


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## hamproof (Jan 4, 2010)

I turned on the humidifier again today and made sure I observed where the first drop of water came from. Here's what I discovered. 

Prior to turning on, I checked inside the A-coil pan and it was dry. Everything else was dry. I turn it on for 5 mins and everything seem normal. I turned off the humidifier only and opened up the panel filter, peek inside the ducts and notice the pan has water. Not evenly filled but rather more towards me (where the outlet is). I put it all back and turn the humidifier back on again. After giving it another 5 mins, I peek inside and notice now the far end of the pan has water, but not enough to overflow. Put it back and waited. Now I hear a dripping sound of water hitting the steel panels. Sure enough water started to seep out on the side of the black tube and also on the outside (the PVC pipe I posted earlier).

I guess there's indeed a restriction as both the humidifier outlet and a-pan outlet are inter-connected and it backing up into the a-pan itself (seeing the water is filling up in the a-pan gradually away from the outlet).

What I don't understand is, the a-pan never overflowed. Perhaps there's a crack? I can't see very well with the coil on top of it. Also, if it is dripping below the a-pan, what's underneath it? How does it get into the black hose?

The black hose should have proper drainage also. Why doesn't water gets collected in the outside box? I remove the rubber grommet and there's water in there.

I guess I really have to cut it apart now and maybe replace the pipes. Perhaps it is a good idea to pipe the 2 separately?

Also, how can I determine if the pan is leaking or cracked??

Thanks.


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## Marty S. (Oct 31, 2009)

Moisture is a byproduct of combustion. Your flue gasses going out the 2" pvc are cool enough that the water actually condenses in the pipe and flows back through the black rubber hose in the last picture. From there it goes through the black box, which is a trap, then out the drain from the black box. Humidifer water or AC drain pan leaks cant get in any of that but it could follow sheet metal and drip on the outside of the pipes.

I'd seperate and clean the humidifier and AC coil drain lines to start. Then you can then plug the AC drain line from the bottom and fill the pan with food coloring and water and check for leaks the next day. A cracked pan will usually leak water into the furnace cabinet.The real problem is probably nothing more then a gunk build up in the 3/4" pvc though.


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## hamproof (Jan 4, 2010)

Marty - thanks for the advice. One follow up question though. If the by product of the gasses condenses and flows back into the black tube, shouldn't the water flows through the skinny black hose into the outside box trap? There's water in the box, even after I drained it last time.

Also, should I be concerned about the water seeping through the black plate where the black hose is connected to the 2" PVC? Any repairs there needed?

I'll get new PVCs and run the pipes again rather than trying to clean them out. Seems easier.

Thanks for all the help. It might take me a while to actually do this, but I'll report back.


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## Marty S. (Oct 31, 2009)

Most of the water drains back from the 2" pvc and into the bigger black rubber hose. Some ,but not much, will come from the smaller hose. If you still have a leak where the 2" pvc glues into the black plastic on the furnace you'll need to replace it. All that hard black plastic and the flange is one piece. There's no way to take the pvc out once it's glued in so the whole assembly will need to be ordered. Don't panic it's an easy job. Running new 3/4" for the coil and humidifier will take you 20 minutes and cost and it's cheap. The other costs a bit more but will be even faster. Took me longer to peck this responce out then the whole job will be:thumbsup:


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## yamahaSHO (May 24, 2010)

It appears that this is a common problem... Here's what I found today.


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## hamproof (Jan 4, 2010)

I'm happy to report the issue was solved a few months back. The curved PVC on the left side was the culprit. It was completed blocked with minerals.


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