We are 95% sure that we are going to switch from our Regency I2100 wood insert to a pellet insert. The top of my list for a pellet insert is a Harman Accentra. I got a quote for $3959 + $450 for installation if a new liner is not needed. Will it be okay to re-use the 6" liner that I have now with a reducer? We have a single story ranch so it's probably no more than an 18' run. The dealer called the Harman rep and he though it would be okay. I just want to check with you guys to make sure that I won't have any draft issues or anything. Also would the 6" liner make it harder for cleaning(i.e. still be able to do leaf blower trick)? Also what about an OAK? The house was built in '76 so it's not super tight. The dealer said it wasn't needed, but wanted to double check because I would probably get one of the ones that uses a double walled vent pipe when it all get's installed if it was needed.