Mysterious furnace condensate leak

[blueman]

A couple of days ago I noticed a small puddle next to one of my American Standard Freedom 90 Upflow Condensing Gas Furnaces (Model AUX080C942C3).

I initially assumed that one of the condensate drainage had come loose or that maybe something was blocked. But the leak has persisted even after thoroughly dissassembling the tubing, cleaning the trap, securing the tubing, and even removing and snugging up the draft inducer motor connections. The chmamber behind the induction motor had some standing water but there was no blockage of the exits. (Note, the connection of the inducer motor with the chamber and with the inlet pipe were loose and showed some condensation but not enough to alone be the source [and I fixed them both]).

After letting the furnance run for a while and inspecting it again, the leaking has continued though I can confirm that none of the tubing or observable connections are leaking. Also the problem is not the condensate pump since it is on the other side of the furnace.

Somehow there remains a reasonable amount of water leaking out (maybe

1-2 oz/hour). Both the upper and lower cabinets are almost completely dry except for a little moisture along one of the edges. This seems to be the only possible channel for the water to the ground though to be honest the amount of water is very minimal (note there are no other physical paths that have any moisture)

It seems to me that the only possible source could be inside the burner chamber (though even so I can't see how it is all getting out).

- Any thoughts on what could be going on here?

- Could there be a leak in the bottom of the burner chamber?

- Should I open up the burner chamber to look further and if so how do I get access?

- Any ideas on troubleshooting or fixes? (if I can't fix it I will of course call a pro)

Google though has not bean my "friend" today and has not been helpful here.

Thanks and Happy Holidays!

[ransley]

At

"the wall" are alot of pros, it sounds like maybe most all condesate is being blocked from draining to the pump. Are you missing any pets, I had a mouse in my ductwork once.

[Nate Nagel]

I had the same issue with my furnace, it was the little rubber tubes in the furnace itself literally rotting apart. Furnace is maybe 20 years old. Went to the Orange Colored Store and got some clear vinyl tubing and some hose clamps. All better.

nate

[Mikepier]

Make sure your drain tubes leading outside are not frozen.

[blueman]

Thanks for the reference!

If it's blocked, then it's internal because the external tubes themselves and the trap are all clear.

Also, I can blow clear into the main condensate tube and feel the air blowing out the draft inducer motor. Also, I still get a reasonable flow out the condensate drain.

So I'm thinking either the blockage is partial and distal leading to overflow somewhere and leakage. Or maybe there is a hole somewhere caused by corrosion or other mechanical defect...

[blueman]

Which tubes are you talking about?

In my situation, the condensate tubes themselves that are in the furnace cabinet (but outside the burner box) are fine.

I have yet to open the burner box itself...which is probably my next step...

[blueman]

Interesting. The condensate tubes themselves are fine (and inside) and in fact are still draining a steady flow of condensate.

If you are referring to the intake/exhaust tubes for the high efficiency burner that is possible I guess but seems unlikely given that the weather wasn't too cold, the pipes are relatively large & short, and there is no really good way for water to get in them (they are above the snowline).