i heat my veggie tank/lines but i don't heat my diesel tank. right now, every time i switch back to diesel the veggie in the return line ends up in my diesel tank...where it is unheated. i think enough of it accumulated to cause a little sluggishness. i'm assuming that oil floats on diesel and that by filling my tank i pushed the oil up out of reach of the fuel intake line in the diesel tank...therefore delaying my having to deal with the problem.

after my valve, the supply lines are all heated, so there really is only five feet or so of diesel line thats unheated. maybe if i wait till summer i can run the diesel tank out with minimal harm. otherwise i guess i'll drain the diesel tank...