[WNY Bullet]

I blow mine out and pump through antifreeze. Blowing out the lines from my City Hookup bypasses the pump and debris filter so water is still in them and could cause damage. By blowing out the my lines first, limits the dilution of the antifreeze from the water already residing in the lines. And of course I also dump antifreeze in all the traps. My Black Tank Flush I just blow out.