This is just a general thought......Last year I was running my owb and for whatever reason I was losing like 10 degrees from my boiler to the furnace and I kinda just blew it off. Today while in the shower it hit me if I am losing 10 in I am losing 10 out that is 20 degrees lost!!!! SO I got to thinking and went under the house and yep there it is in front of me I forgot to insulate 2 lines in and out about 4 or so feet long!! So mission for today insulate the lines and hopefully a longer burn time!!!!