been posting a lot lately, thanks for all the help.. lineset question.. 18 seer 2 stage Goodman HP, 3 ton, with matching cased coil. My installer says the lines coming out of the coil and HP are 7/8". I downloaded the manual and there is a chart that says 3/4" lines are fine for a 20 ft run or less, my run will be 14 feet tops. The installer does not want to use the old lines, he wants to run new ones to be completely safe. I think this is great. He wants to use 7/8". That is fine with me, except for what the manual says.. so my question is does it matter if the lines are possibly too big? Thanks, Mike.