The following below, is a prime example of a post by someone you do NOT want
working on your units.
Looks good (to a layman) sounds good (to a layman), and is total bull****.

"Bob" wrote in message
...
I've worked on thousands and thousands of oil burners. I've seen several
smoke pipes installed down hill and I once saw one over 40 ft. (pitched
properly), and they worked fine. There are a few things you need to be
careful of.
1) Make sure the chimney flue liner is sized properly. Do not oversize it.
8
x 8 covers most Weil-McLain residential boilers.
2) Make sure the chimney is high enough above the peak of the house, and
not
obstructed by trees.
3) Make sure the smoke pipe goes up hill. 1/4" per ft. is good. If the
boiler is convertible from a top flue to rear flue, put the smoke pipe off
the top if you have enough pitch. If not, put it off the back. The pitch
is
the more important of the two.
4) Do not 'bull-head' the draft regulator.

The 25 ft. vertical chimney is going to help (not hinder) the draft, as
long
as the chimney is warm and dry, you should be ok.

wrote in message
oups.com...
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.

Thanks.