I have two SS Brewtech 7 gallon Chronical fermenters with the FTS2 cooling and heating system + an SS Brewtech Glycol chiller. Recently, I have been experiencing air leaks in the seal between the coil and the lid. I have tried tightening the nut on top of the lid, have tried using keg lube on the o-rings and have tried replacing the old o-rings (16mm x 1.8 mm) under the lid and on top of the lid with little success. Any suggestions on how to fix it? Can I or should I use larger o-rings? If so, what size (thicker or wider? Under the lid or on top of the lid?) Below is a picture of one of my Chronical/FTS lids with hoses. Any thoughts or suggestions would be appreciated.