Gas Furnace Venting Into Chimney

Hello, first time posting here. I recently had a new roof put on and had the old chimney removed. They put a vent on the roof over where the chimney stops inside my attic due to the fact that the gas furnace is venting through the chimney. I recently noticed that I have some condensation in my attic about 5 feet around the chimney. In the attic there is a space between the chimney and the roof about 4 inches wide. I am thinking that heat escaping the chimney into the attic is causing the condensation in the attic, but that is a guess. The pipe comes through a closet before it takes a turn into the wall and into the chimney. I wondered if having this go straight up and through the roof was the better option. I'm not sure what is considered 'code' and I certainly don't want carbon monoxide leaking. Anyone help or advise would be great.

 

Welcome to the forums.

I'm having a hard time visualizing what you have there. Can you take and post a few pictures for us ?

http://www.doityourself.com/forum/el...-pictures.html

 

Alright- here are two pics- one shows the chimney inside the attic in the background. The other shows the vent on top of the roof where the chimney came out at one point. So it is directly above where the chimney meets the roof in the attic. It's a small pic but you can see there is a small gap between the chimney and the roof-line.

 

That chimney comes up from the basement and they cut it off in the attic and just stuck a cap on the roof.

Is there a metal liner/pipe that is inside the chimney and connects directly to the furnace ?

 

I honestly don't know- the pipe that goes through the wall and into the chimney is metal. Does that help?

 

I am told that I need to have a doubled walled pipe installed and that it needs to go all the way to the roof and out- the pipe is supposed to be 4 ft above the tallest peek. Does this sound correct to anyone? Apparently several years ago the code was changed and it is no longer legal for a furnace to vent into a chimney. My insurance company could cancel my insurance due to this.

 

Did they use the existing chimney as a chase way or as the actual vent? If it's used as a chase, then the pipe needs to be ran from the roof down to the unit in double wall. If the used the chimney and just stuck a piece of pipe in there, it's probably back drafting into the attic. Looks like a poor mans chimney liner attempt.

 

Check with your building inspector for your city. In my zone, 18" above a 90 deg angle to the higher pitch of the roof. I can't imagine going 4ft above where your peak is. It does need to be double wall or lined from the basement with expandable stainless steel flex. You can put fiberglass insulation around any gap at the old chimney in your attic. Somewhere it would have to transition to solid before the flex went out the roof, so I'm "guessing" solid all the way down.