Hey guys, quick question. I just grabbed a new quadrafire 3100 insert for free from a guy down the street and I just need some professional opinions before I finish up the install. The fireplace I'm putting it in has a shared chimney with my furnace. 2 different clay lined flues. Up top I put a shared cap on about 3 years ago. My question is would it be ok to leave the large cap on and put the new liner through the plate but not make use of the cap that came with the kit?