Where should I drain condensate from a high-efficiency furnace?
I have a high-efficiency furnace, installed in 1995 and I now do not think the condensate drain was installed correctly. It has now corroded and is leaking inside my basement.
The condensate line was run from the pump through 39 feet of 1/2′ clear flexible “fish tank” tubing up into the exposed joist area in the utility room and over to the laundry drain pipe. The run was secured to pipes and things by looping it around objects and with tape. The drain end of the tubing was attached to a 6″ piece of copper tubing (3/8″ I think but I can’t tell now) and that was stuck into the laundry drain.
The copper tubing has now corroded away and the drain is now hanging free dripping on the floor behind the washing machine.
Here are what I think are my issues. 1) I have a septic tank so I do not think they should have ever drained the acidic condensate into it. 2) it is a 1966 house and has galvanized drain pipes and cast iron sewer pipes, not more modern plastic, so I do not think they should have drained into those pipes where the acid could corrode them. 3) From what I have gathered online there may be an issue with there being enough of an air gap with the washer and condensate line both into the laundry drain. 4 )I live in Massachusetts where I am guessing they didn’t drain it outside because it could freeze in the winter.
But I have noticed when walking my dog that there are other houses in the neighborhood with small pipes going outside near the plastic flue pipes in some homes. So I am guessing they must be other high-efficiency furnaces and I am guessing the small pipes are the condensate drains. In a couple cases, it looks like there is a separate 1/2 or 3/4 PVC pipe coming out of the wall. In another, it looks like there is a small drain pipe inside the flue pipe leading out. Maybe this was done somehow to keep it warm in the winter to keep it from freezing.
Can I redo the drain to go outside? How? I can’t find instructions online. Maybe someone can point to them if they are there.
I am concerned now that the contractor may have messed up bad enough that I worry about the galvanized laundry drain in the wall and about the cast iron sewer below the concrete floor.
Do I need to open the plaster wall and check the laundry drain? Do I need to hire someone to run a camera to inspect my main line? If I do and there is a problem how do I get the installer to repair it after this length of time?
Thanks for any help or advice anyone can provide.