Where I live, temperature is generally below zero in February. (MICHIGAN) it is very important to get all of the water out of a trailer either by blowing it out, or by purging the system and then filling it with RV antifreeze.
I had time this year and decided to do it myself. I got out the owners manual and did it according to the instructions. It was a shame that I had to waste $12 in antifreeze just to fill up the hot water heater, but as I said there is no way to put a bypass in without removing a couple of kitchen drawers.
Once everything was running a bright pink, I talked with some neighbors and ask them if it was important to leave antifreeze in the lines charged for the winter. Some do, some do not. I opted to drain it. That way I know that anything residual that is left in the lines, at any low point or joint, is pure antifreeze and not water.
My original question was, does it matter whether the pipes are charged and full or not? I can't see why it would matter. I do appreciate the other comments.
