Water – What are these two pipes coming out of the house


I am trying to figure out the purpose of a couple of pipes that are currently coming out of the house.

First, a couple of notes:

  • One-story house.
  • HVAC system is in the attic.
  • It is winter here. Running the heat. Using the water heater (which is in the garage). Not running the A/C.

The first pipe, shown here, I am pretty sure is the emergency drain line for the HVAC system. It is coming out from under an eave near the top of the house. Can someone verify that I am correct? It is not currently dripping.

Emergency Drain Line???

The second pipe is the one that I am not very sure about. It is actually dripping slowly, but steadily. I would say one drip every 3 seconds or so. It has been raining here, but I can't imagine this pipe having to do with draining rain water. Like I said, we do run the gas heater daily. And the hot water is, of course, used daily as well. The water heater is on the other side of the house in the garage. Any thoughts as to where the water from this pipe is coming from?

Not sure what this pipe is for

Best Answer

High efficiency furnaces will make condensate. They run the air back through the hot exhaust to get more heat out. This also cools your exhaust enough to use PVC - that's what your upper line is.

In the process of cooling the exhaust, you might get some condensation. Typically that's collected in a little sump tank. When the sump reaches a certain level, a little bitty pump pumps it out - that's your lower line.

If it freezes where you are, you might want to insulate that lower line. If it freezes shut, your sump could overflow in the mean time. It's just a dribble of water, but still. It's a leak of water in your attic.