You need to call in a professional to assess what s going on.
Furnace pvc exhaust pipe leaking.
A clog or issue in the condensate system.
A standard efficiency furnace extracts some heat from the combustion gases and quickly vents them out the exhaust or flue pipe.
If you have a condensing furnace it s likely leaking due to any of the following issues.
A bad heat exchanger.
To see if the issue is the vent pipe follow these steps.
If there is an issue with the condensation pump you will usually be able to see water dripping from the pump.
Here s what to look for.
That way should there be a problem with the furnace that causes the exhaust temperature to exceed design the exhaust vent system has almost 40 more capacity to handle the excess heat before it reaches the point where it can fail.
A poorly sized flue pipe.
You can prevent slime and eliminate drain tube clogs in two easy steps.
Condensation from air conditioning coils contains bacteria that can form slime and clog the condensate pan drain tube.
A condensate pumplooks like a small white box connected to the pvc drain pipe on your furnace.
When you see water puddling around the furnace with the a c running you have a clogged condensate drain tube.
As the gases sit in the flue they cool eventually forming condensation which can leak out of your furnace into the surrounding area.
There should be no water involved with a standard efficiency furnace.
If you have a condensation leak with a standard efficiency then its exhaust or flue pipe may be incorrectly sized.
Look at your flue pipe.
If your furnace exhaust pipe or flue pipe is leaking it can be a sign of a much bigger problem.
To be more specific the pipe that comes out of the unit is attached to this leaking section which is attached to a pvc elbow then another piece of pipe and so on.
Bad clogged condensate pump.
Today i noticed water leaking from a section of the pvc exhaust pipe which travels upward from the furnace across the ceiling and out of basement wall where it vents into my backyard.
Despite the confusion the safe practice would suggest the use of pvc schedule 40 pipes for the air intake vent on the furnace and cpvc for the exhaust flue vent given its higher service temperature.
However if your exhaust pipe is too big or it has no slope it allows too much air to circulate and traps the gases in the flue.
Its job is to pump water toward the drain.
If he or she rules out a condensation leak there are other possibilities all still requiring a professional.
