I had forced air installed in my house a couple of weeks ago. As part of the install, the company ran a copper pipe from the attic (where the unit is) down through one of our walls and out into a drain pipe located in our house. This pipe is shared by our washing machine, and is located between our washer and dryer. They rough patched the hole, and did not fill it with drywall, simply patch.
3 days later I noticed a smell - musty, like mold - coming from behind our washer and dryer. I couldn't figure out where it was coming from - other than the odor was emanating from that general location.
This odor has persisted, and grew in strength, to the point where my wife and I can smell it in the entire room.
Two days after this I noticed a faint yellow stain that was present on the lower portion of the patch. It started where the patch met the drywall, and radiated in both directions. The next day I was sure that the stain had grown, so I marked it's outer limits with a pen. Sure enough, the stain continued to grow, at roughly 1/5 of an inch a day or so. With the city set to inspect, I called the company that installed the system to inform them.
They arrived today, turned on our unit, and observed. After a few minutes, the individual from the company stated that there was moisture building up along the copper pipe. He let me know he would be replacing it with clear plastic piping.
He removed the old patch, removed the copper tube, replaced it with the clear tube. He also wrapped the clear tube (the portion that was inside the wall and he could reach) with what looked like wide silver tape. After this, he crammed a significant amount of insulation in the wall, surrounding the tube, and then rough patched the hole up.
While he was going back to his truck to get supplies, I felt around inside the hole before it was patched. The drywall did feel damp - which I brought up to him. He hacked a bit more off in response. I also snapped a couple of pictures. Unfortunately they are after he removed most of the patch, but you can still see most of the stain including the lines I made with my pen.
I'm curious what caused the leak in the first place, and if this is something I should be concerned about in the future. Additionally, the smell has not gone away. Granted, he only left an hour ago, but should I be worried if the smell does not fade in a few days?