View Full Version : strange furnace install

Matt Fellman
09-18-2007, 01:55 PM
This is just wrong and I'm calling for further assessment... any comments?

The intake is in an unfinished attic above, the output sticks straight up like a plumbing vent which would seem to collect water... although maybe not quickly since the pipe has negative slope above the furnace. The inside of the furnace case is rusted and there are no collars around the pipes where they pass through the ceiling.

I'm mainly curious about the exhaust termination above the roof. Usually, aren't they pointed down or at least sideways? I thought is was a plumbing vent at first.

Jim Robinson
09-18-2007, 04:32 PM
Some are straight, some are not. Is this a Cat IV furnace? There should already be some way of removing the condensate drainage if there is, making the top of the pipe not as relevant. Some manufacturer's have them straight so that it doesn't drip onto the roof and stain the shingles. The rust would be my biggest concern with the setup. Is the attic vented? The intake from a vented attic shouldn't be a problem as long as it isn't causing a negative pressure problem inside the attic space.

The negative slope will be a problem on the exhaust flue. Is this where the rust is coming from? Usually these furnaces are new enough that you can find the manufacturer's instructions at the house on on the web.

Jon Randolph
09-18-2007, 07:41 PM
I would not worry about the exhaaust vent collecting water. If any gets into it it should either go into a condensate pump or to a drain. I would be concerned about the proximity of the vent to the soffit/gutters. Even though these furnaces are "condensing" furnaces, they still expell moisture which could be forced into the attic area.