I am currently doing some basement renovations on a newly purchased house (built 1985). There is a hole cut out in the drywall to access a small box on the furnace. The Furnace is original. (sorry can't get the make and model at this time)

the box is approx 1 1/2 ' X 1' box on the furnace duct. Directly above the actual furnace. (not on the cold air return). There is a water line running to it but there is no drainage coming out of it. The box is not labeled or anything. There is also a humidifier installed and attached on the cold air return. Leaving me to believe that this is not a humidifier of some sort.


Sorry for the lack of info but can anybody give me any ideas of what this could be?

Sorry I did not mention that this is a natural gas furnace. I will get the Make and model once I get home from work.

Yes it is an old type humidifier it sounds like. Some used a float to fill up the reservoir and then stop the water when full. And some actually atomized the water into the air stream, the problem with those is it also atomized all the calcium, rust, sulfur etc. Not to good for your lungs to breathe all the time.

Ya I opened it up last ngiht and like you said there is a float and a water tray and it is full of calcium build up. Thanks very much for your help.