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michrob 01-29-2010 04:20 PM

Water Inside/Around American Standard Furnace
Hello All,

I am looking for some information regarding a strange problem with my furnace this morning.

First some background information. The furnace is a 4 year old American Standard Freedom-90 Dual Stage Comfort-R Furnace model AUY060R9V3W. Its installed upright, has PVC Fresh air combustion pipe as well as PVC exhaust pipe. These 2 pipes raise up from the furnace, follow a floor joist and exit my house via two large holes. Two years ago had a American Standard Allegiance 13 Central Air installed.

It was a very cold night last night here in Michigan(5F). This morning I was greeted by water around and inside my furnace. It even flowed to the floor drain. The first thing that entered my mind was the condensate pump not working. I ruled this out by testing it, adding water with a baster and watched it come on and off, several times. The water I was seeing seemed to come from inside and flow out from underneath the furnace. My second thoughts was a leaking connection on all the condensate hoses inside. I dried the furnace bottom out(wiping it with towels), and using an air compressor blew collected water from underneath the furnace. In the furnace, the area underneath and to the left side of the blower, had several puddles of water. This area is raised up about an inch because its actually a plate that is removed if you install the furnace in the horizontal position. After drying it all out, I taped the shutoff button in the ON position and letting the furnace run while I looked for any leaks. I could not see any!! Everything is still dry(6 hours later) and the furnace is running alot because its very cold here. I watched for hours, each condensate connection and no leaks, all is dry. This was a real mystery for me. Here are some things I did:

1) Inspected all condensate hoses for leaks or loose connections.
2) Inspected combustion air intake and exhaust gases pipe. No
3) Took the cover off the condensate pump, watched it work and work.
Never once did it malfunction.
4) Visually looked into the close combustion area(where the flame tubes are located) for evidence of water. The fresh combustion air pvc intake pipe is directly above this area. No evidence of any water.
5) My estimate would be there was about 1 cup of water on the furnace floor plate to the left and under the blower motor. The entire amount of water(that that flowed underneath the furnace, to the floor drain and including the water I blew out from underneath with compressed air) I would estimate that leaked would be perhaps 2-3 quarts. Just guessing!

Some other information, if the condensate pump did happen to malfunction then the water would not have been inside the furnace, on the floor plate below and to the left of the blower. It would have to go up hill to even get to this area. The pump is mounted on the left side of the furnace and sits on the floor. If it was leaked or overflowed sure water could get under the furnace but it would not be able to get up onto that plate under the blower motor. Another thought. Last night was very cold(5F) could this have had any connection to this water leak? In the 4 years since it was installed, almost every winter it gets that cold too but never had any water leaks anywhere. A futher thought..the A/C Condensor sits on a pan, above the combustion chamber, in the furnace plenum. The pan it sits on has a pvc drain pipe on it that exits the plenum and makes a right angle down straight into the condensate pump.

If anyone has any ideas what caused this weird leak I would be most gracious to hear any comments or things to further investigate. As I mentioned, I noticed this at about 8AM this morning. The furnace had been on for about an hour. Not sure exactly when the leak started but my guess it was this morning when its programmed to go to 71F after being at 60F during the night. It did come on a few times during the night. Also it has been running since about 10AM until now(5PM) and still no signs of a leak anywhere. Surely if there was a leak it would have been seen by now. This is why I am wondering if it being not running most of the night and being very cold had something to do with it.

Thank you for taking the time to read my message.

PS: I have 2 water detectors on the floor around it now. I don't rely on them solely, I physically open the furnace up and look for any water. In fact the water detectors/alarms would only sound if the water leak was significant and flowed from underneath the furnace.

yuri 01-29-2010 05:19 PM

Cold air can migrate into the furnace via the intake pipe and if the furnace is off long enough cause condensation on the heat exchanger which may drip. Usually that happens with 3" venting and in a very cold climate like mine. I usually recommend people don't setback their thermostats more than 4-5 degF. If it happens again you may have to remove the blower and check for evidence of water inside it which means your secondary heat exchanger may be leaking.

michrob 01-29-2010 05:50 PM

Yuri...Thank you very much for that valuable information. Yes its 3" pipe. I keep my thermostat at 60F at night about 71F during the winter years. This is the first time this has happened. I'm very disappointed with this brand of furnace. I had one
prior to this, new installed, and after about 3 years was continuous problems. So, 4 years ago had it replaced with this same
brand but highest model. BIG MISTAKE!! I thought for sure this will be my last ever furnace purchase...Now I'm not so sure
of that. I really appreciate your time sir. Its gonna be another cold one tonight so I'm not gonna sleep so well.

michrob 01-30-2010 12:26 PM

This is for Mr. Yuri...

During the night again there was water on my floor around/underneath the furnace. This time though I think the problem is solved. I just wanted to let you know more about it Yuri because you took the time to reply. Well as stated, there was water around the furnace again this morning..NONE inside though. I had a service tech come out this morning. He checked the condensate lines for blockage..none found. I had him replace the condensate pump because I felt this
was where its coming from, and the tech thought so too since no water was inside the furnace on the floor plate. After the replacement pump was put in and the tech left, I disassembled the bad pump. The float had a 1 inch Y shaped crack in it and it was 99% filled with water!! Shaking it makes water come out. Ahhhhhhhh Haaaaaaaaaaa... I suspect this to be the problem. Some other thoughts: Why did it work OK all day though? In my opinion was because the condensate was getting a lot of water at a time(2 stage furnace). During the night the furnace would come on single stage only, for about 10 mins at a time. Thus a trickle of condensate into the pump tank. I feel this slow filling and the water in the float caused it not to raise high enough TOO GRADUAL thus not making the switch lever move to the ON position. Unfortunately the pump was replaced with the idential little giant condensate pump because thats all the tech had. To me, after only 3.5 years and the pump float cracked and failed does not give a very good representation. How did water get inside the furnace? My suspicion is the morning this happened the furnace was on for a good hour or so, in second stage. The blower motor, I presume, sucked the leaked water from underneath and around the furnace into it! This furnace blower on second stage is very powerful. With the two access panels off and the saftey switch taped(so the furnace will run with the panels off) the suction in my basement is so powerful it will PULL my kitchen door closed(upstairs, the door entering the basement). So this is how I think water got inside!

In the end I will know for certain tomorrow morning if its fixed but I am pretty darn sure it is especially after seeing the float filled with water.

Again, thanks Yuri. You have thousands of posts here and I am sure each and every one of them are very appreciated.

Good luck.....

PS: If I don't post another follow up to this post tomorrow morning(1/31/10) then be assurred the problem has been solved.

yuri 01-30-2010 12:53 PM

I love a great detective story. :detective: As long as I am not doing it in a dirty crawlspace at 4 PM on a Friday. LOL.:thumbup:

ChrisWNY 11-01-2010 10:22 AM

Sorry to "resurrect" an old thread, but I am seeing the same problem with my own 3-yr old American Standard Freedom 90 furnace (it's single stage, not dual stage). Recently, I have noticed water underneath the furnace now that heating season has begun. The furnace uses LP gas for heat, and we have the same PVC fresh air combustion/exhaust pipes. I removed the covers from the front of the furnace and cannot for the life of me figure out where the water is coming from, and I'm not sure how to gain access to the condensate pump - if it needs to be replaced, I might as well put a call into the plumber who installed the furnace into my house when it was being built in late 2007/early 2008. The furnace is used for A/C also and had ZERO problems with water underneath the furnace over the Summer.

Is it most likely a leaky heat exchanger? I don't have a condensate pump, water from the heat exchanger passively flows out into a floor drain.

callaghan 03-28-2011 08:43 AM

Water Inside/Around Carrier Furnace
Wondering if anyone else has experienced this problem or found a solution (I have a Carrier furnace). I do not have a condensate pump either but water leaks out the bottom of the furnace. I find a puddle on the floor first thing in the morning, then it is fine for the rest of the day. I have opened the furnace up and can see water at the back of the furance, nothing in the furnace itself appears to be wet other than the floor pan.

Two furance technicians have been by to look at it and cannot find anything wrong. Water does not appear to drip during the day.

KamaBama 12-08-2011 12:14 PM

Water Inside/Around American Standard Furnace
I have recently had the same water/condensation problem with my American Standard Allegiance 13 (2009). I never determined where the water was coming from. The tubing and access points of PVC pipe were full of water, but the water was coming from under the bottom of the system in my basement. I took a turkey baster (don't laugh, it worked!) and drained the water out and then used it to pump air in the tubing and added more Clorox. I presume the line was clogged, so I thankfully no longer have the water problem, but now my furnace will not come on. Is there a safety kill switch that may have been activated due to the water? The unit comes on and the air blows, but the furnace will not kick on and heated air does not come out, just cool air. It has turned COLD here and at the holiday season, I really don't have the extra money to have a service tech come and look at it IF I can fix it myself.
Any ideas?
Thanks in advance!

harleyrider 12-08-2011 03:51 PM

Seems that Trane/American standard (They are the same products with different names) seem to have inherent condensate issues, mainly its from restricted ports were the condensate leaves the inducer housing and travels down to the condensate trap.i advise starting by cleansing the trap and lines with a warm water and bleach solution. most of the time this will solve any condensate issues.

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