Hello, I came across this forum because I have a problem. We are currently having a bit of a heavy rain and I heard water running from behind my furnace. I'm posting this here because of the location of my problem but if this is the wrong forum, I apologize. The source of the leak is pipe that is a little less than an inch in diameter coming through the foundation right under my furnace vent. I had never noticed it before but water is coming in pretty good. Does anyone have any idea what this is? And how I might fix the problem?