Re: BOSCH upright frost-free freezer – icicles forming!
The most common cause of this , if i read the description right , would probably be a blockage of the drain hole by some ice at the rear of the evaporator. As the appliance goes into a defrost stage , the defrosted ice has nowhere to drain , if the hole’s blocked , and so the only place for it to go would be back in to the freezer compartment. Hence the icicles forming and , normally , a solid block of ice under the bottom tray.
As its a GSU model , i would reccomend a full 48hr defrost, appliance switched off and door left open , with a few towels around the base. This should clear the blocked drain hole of ice and get your freezer back to basics.