Prior owner of my TT "claimed" to be a master plumber, who taught the trade at a local community college.
First found problem, sealant used on a propane flair fitting (one the FLAIR SURFACE) going to the brand new water heater he installed. Might have actually worked if he had tightened the nut...
So, I went to pump pink stuff through the lines to winterize the TT, and after pumping the first gallon on the ground had my wife go check to see if in fact it was spilt, and it was :(
Spend some time noodling the crazy plumbing, make a couple of changes and do it again, and still pumped pink stuff on to the ground. Finally figure out there no back flow preventer into to water heater. At this point I'm wondering how water even comes out of the water heater without a back flow preventer.
With the proper application of shut off valves, disconnected lines, capped ports, finally got the lines winterized. Will have to do it two more times this winter.