On 22 Dec 2005 06:13:11 -0800, wrote:

My last thread got hijacked, so I am posting again...

I have a Weil-McLain boiler (5 years old) and it is vented with a power
vent and intakes combustion air from inside (basement).

I am installing a fireplace on the main level and will be building a
chase for the chimney on the outside of my house. I was thinking this
would be a good time to convert my power vent to a real chimney for
long term durability as I could share the chase with both chimneys. I
don't know if this is feasible though since my boiler is not located
real close to the location of the fireplace. The boiler vent would
have to go 6 feet horizontal, then right angle and another 12 feet
horizontal then vertical for 25ft chimney height. Of course when I say
horizontal, I mean it could go at an incline when it is horizontal. I
would have a professional do all of this, but was curious if this is
even possible, or would I screw up the drafting and cause
condensation/soot problems?

Trying to educate myself before I call the pros. I really don't like
the powervent due to noise/smell outside the house. I could build a
new chase right above the boiler just for the boiler vent, but that
would be more money and time...trying to avoid.

If the boiler is a total of 18 feet offsett from where you want the
fireplace, then I'd say, no it's not a good idea to try to share
the stack with the chimney. (Probably possible, but not a good idea)
I'd say either put the new fireplace closer to where the boiler is,
move the boiler, or use two stacks.

My personal preference would be to re-think where the fireplace
goes, and stick it on an interior wall, but your floor-plan
or budget may militate against that.