Freezing evaporator?

[mike z]

Ok, first year with a more traditional evaporator (channeled 2 pan system). Still outside though. What precautions should I be taking for when the temps really drop? It may get down to single digits here in a couple of nights. Should I drain the pans completely or block the openings with stoppers, and drain the U connection between the pans? Thanks for the help.

[maplecrest]

when it gets really cold i drain the rig but if near syrup the ice will come to the top and the heavy sugar will stay low protecting the pans.