Had an Exterior Patio Door installed 5 yrs ago.. We access the Backyard off the Back Deck.. Problems begin once the Temps dip below (-10'C) The track will Ice Up and becomes difficult to close tight.. Ideas what could be leading to the problem ?? The nearest Heat Vent is to the left of the patio door..

Most any deicer spray should help a lot and we use a silicone spray for the slides. It's not like we use the patio door a lot when its that cold, matter of fact we keep the blinds closed as a layer of insulation. I would imagine though your cold temps last a lot longer than ours do, and you have much more moisture in the outside air.