Side-by-Side Units: the Freezer Section (BI-42S / BI-48S)

A tall, narrow freezer

Splitting a built-in down its height gives the freezer the full height of the cabinet but only part of its width. Air cooled on the coil inside the compartment is pushed by a fan through a long, slim space, and when anything weakens that airflow the upper baskets tend to be the first to notice: soft ice cream above, rock-hard peas below. That is the pattern behind soft ice cream at a displayed 0°F, where the display reads the setting while the food says otherwise.

Three things produce it. The fan inside the compartment slows or stops. The coil it blows across has iced over because a defrost part is no longer warming it, so the air has nowhere to go. Or the board that reads the sensors and switches the fan and the defrost is making the wrong decisions. From the front the three can look the same, which is why the fault is metered before a part is named. The cost page on a freezer not holding 0°F walks through how each of them is priced.

The fresh-food side is a separate job

Because each side has its own system, a side-by-side can fail on one side only. If both sections have gone warm together, look first at the breaker and at the grille above; if only the fresh-food side is warm, that work is priced on the refrigerator repair cost page rather than here.

Dispenser models add an ice and water system through the door. Ice faults are their own subject and are not covered on this page.

What an owner can check

Sub-Zero presets the freezer side at 0°F, so confirm nobody has nudged the setting. Look for a basket that is not sitting fully home, which holds the door off its seal, and for frost in a line down the door edge. Check that the grille at the top is clear. The condenser behind it wants cleaning every six to twelve months, according to Sub-Zero’s instructions for these Classic units; do it with the power off at the control panel and gloves on.

Asked about this unit

Does the freezer side of a Sub-Zero side-by-side share its cooling with the refrigerator?

No. Sub-Zero describes these units as Dual Refrigeration: the refrigerator and freezer have individual systems, each with its own temperature setting. The owner's guide even explains how to switch one section off while the other keeps running. So a warm freezer beside a cold refrigerator points at the freezer's own parts, not at the whole unit.

Which side-by-side models have a dispenser, and does it change the freezer repair?

Models ending in SD, such as the BI-48SD or the current CL4850SD, carry an ice and water dispenser; on the current CL models it sits in the door. The freezer's fan, defrost and board work is the same either way. A dispenser fault is a separate diagnosis. Sub-Zero Repair Kirkland, (425) 699-2400.

A freezer basket on my narrower side-by-side will not come out. Is it broken?

Probably not. On the BI-36S, BI-42S, BI-42SID and BI-42SD, Sub-Zero's guide says the basket has to be released, then raised and passed through the opening in the door liner. On the wider BI units it lifts off its slides once the two metal clips behind its bottom corners are pulled forward.