Does double wall black flue pipe ever need to be replaced? I took out the Liberty and brought Progress Hybird down into is spot. I was going to replace the telescoping pieces because of the different placement of the 3 screw holes and keep the 2 45* elbows but didn't know if there is a life span on the flue it self. The black pipe is about 9-10 years old. Total replace cost of all new black pipe was about $225 yesterday at Menards. Thanks Fespo
