Sub-Zero Freezer Temperature Varies

MFMauceri

Member
Joined
Jun 14, 2019
Messages
8
Location
Los Angeles
Model Number
661
Brand
Sub Zero
Age
6-10 years
I have a Sub-Zero Model 661, double sided unit

The Freezer Temperature Varies in two ways:

1. The temperature thermometer reading (on refrigerator panel display) reads anywhere from 0-27 degrees depending on how much of the freezer is loaded (More items = Higher Temperature (reading)).
2. Food in the rear of the freezer is thoroughly frozen (solid), while food in the door shelves is not; example ground beef is pliable when stored in door and frozen block solid in rear of unit.

Coils are clean, compressor is "normal" temperature; hot but not burning hot. Door seal is not leaking.

This seems like a circulation problem (fan?), but could be other? Anyone experience similar symptoms and have good idea what the issue may be? Sub-Zero authorized reapair is a minimum $500, and if it's a part replacement, I can do that, but would be more comfortable with know where to look first.

Any thoughts welcome.

Thank you.
 

Dan O.

Appliance Tech
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Messages
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Food in the rear of the freezer is thoroughly frozen (solid), while food in the door shelves is not;
Has anyone confirmed operation of the freezer fan motor?

Either the fan isn't operating or there's something else hampering air movement throughout the freezer compartment. The latter could be due to a frosted-over evaporator or air ducts being blocked by food packages, etc., or ice.

Dan O.
 
Last edited:

MFMauceri

Member
Joined
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Messages
8
Location
Los Angeles
Has anyone confirmed operation of the freezer fan motor?

Either the fan isn't operating or there's something else hampering air movement throughout the freezer compartment. The latter could be due to a frosted-over evaporator or air ducts being blocked by food packages, etc., or ice.

Dan O.
Further evaluation indicates the evaporator fan motor (freezer side) sounds a bit wonky, like it's struggling (or not running at full speed). My guess is it's either the motor, the blade, or both (maybe a capacitor?). As we empty the freezer if items, the temperature gets down to the set point of "00", yet door items are still not frozen. Once empty, I will open up the panels to see what's going on. I have culled the part #'s, and am looking for a reasonably-priced source for the OEM parts. This model defrosts every 24-hours (or so I'm told) and I think if stored items/ air flow are the problem, then we would have experienced this sooner. Really hoping it is the fan/blade, as that seems like a 1:1 repair.

Thanks!
 

Dan O.

Appliance Tech
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Really hoping it is the fan/blade
I've never seen a fan blade causing a cooling problem in a refrigerator unless it had fallen right off. And I've never seen that.
 

MFMauceri

Member
Joined
Jun 14, 2019
Messages
8
Location
Los Angeles
The fan blade WAS indeed hindered, but that was because it was hitting ice build up on the coils until it eventually stopped spinning. I have manually defrosted the coils--- and the fan/motor/blade are spinning optimally, but that seems like a temporary fix. I will look in the forum to see if it's possible a thermostat or control board issue. But, you ARE right, it was not the fan (or root cause, anyway).

Thanks.
 

Dan O.

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MFMauceri said:
But, you ARE right, it was not the fan
I said it was not the fan BLADE. I did indicate the fan MOTOR being inoperable was a possibility.

If it frosts excessively again, I agree, someone will need to look into why.

JFYI
 
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MFMauceri

Member
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Messages
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Location
Los Angeles
Yes, I was agreeing with you, fan (and blade!) now spinning properly, but freezer not getting past 41 degrees (has immediate frost buildup on left side of coils only). No error codes coming up after putting unit in diagnostic mode. Thought it might be a thermistor/defrost cycle issue (no mechanical timer on this model), but fear it's a closed system problem, too.
 

Dan O.

Appliance Tech
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Joined
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Messages
2,143
Location
Canada
MFMauceri said:
has immediate frost buildup on left side of coils only)
That sounds like a refrigeration system problem. You'll likely need to get a professional in to look into it further. :(

Dan O.
 
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