Are you using vertical or horizontal nipples? The vertical ones do tend to freeze much faster than horizontal nipples. I use horizontal nipples and live in NW Montana where -20 F is not unusual. My nipples have not frozen yet after 4 years of use.Do the nipples freeze up? I checked last night (5 gal plastic bucket with a deicer in it. Tin layer of ice on top but the nipples seemed hard. Like frozen hard.