subzero 650 ice in freezer even though water supply is disconnected

[ale6]

So fridge and freezer running fine.

Whenever, I open freezer and close it, it would make a hiss noise. Later when I open it, there's ice all over freezer or food.

Once in a while, there would be some puddle of water on bottom of fridge. I have cut off the water supply, so it's not that.

I have check the drainage tube in the fridge part, pour some bleach water down it, it drains fine to the pan underneath the fridge.

What could be the issue?

[Hiroshi]

Look for a break in the door gasket along the bottom, or perhaps it has pulled loose somewhere?  Frost is almost always a sign of warm air inundation, make sure the shelving is in place and allowing the freezer door to close... Sometimes the pattern of the frost will give you a clue as to where the warmer, and therefore, more humid air is getting in.

[ale6]

5 minutes ago, Hiroshi said:

Look for a break in the door gasket along the bottom, or perhaps it has pulled loose somewhere?  Frost is almost always a sign of warm air inundation, make sure the shelving is in place and allowing the freezer door to close... Sometimes the pattern of the frost will give you a clue as to where the warmer, and therefore, more humid air is getting in.

i'm not talking about frost.

I'm talking about ice like this picture, but it's not the drain freezing: 

[Hiroshi]

there is a foam gasket behind that drip pan, looks like it is leaking behind the pan before it gets to your drain hose. remove the pan and inspect the foam

[ale6]

8 minutes ago, Hiroshi said:

there is a foam gasket behind that drip pan, looks like it is leaking behind the pan before it gets to your drain hose. remove the pan and inspect the foam

ok, that make sense on the puddle on the floor. Any idea about the ice in the actual freezer area?

[Hiroshi]

there is a constant dripping on the fridge side, because the fridge evaporator should never reach 32 degrees. The freezer should automatically defrost every 8-10 hours and creates water which must be drained... Most sub-zeros have heater kits that fish down the tubing to prevent freeze-ups.

[Hiroshi]

Don't be afraid to call Sub-Zero, they are good about helping techs and homeowners alike... Have the serial # ready