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.

Thanks.