Wow, that the same setup I installed on our F350, and I don't recall reading that. I assume it is to prevent condensate from freezing make your bags non-operational. We never really used ours in the winter so I don't know if they ever froze or not.
Brad & Dory - Lone Tree, CO
CURRENT - 2013 Itasca Meridian 42E/2013 Wrangler 4dr Sahara
SOLD - 2014 Redwood 36RL/2014 F350 DRW