Why does my undercounter unit only struggle in summer?

Because it has less margin than a full-height cabinet and usually far less air. An island unit has cabinetry on three sides; a bar unit often breathes its neighbour's exhaust. In July the air it draws is hotter and wetter, so a unit that held its temperature in March has lost the headroom it was running on.

Why does a refrigerator drawer freeze what it should only chill?

A drawer is a small volume fed by a duct or damper sized for exactly that volume. When the airflow stops being metered the way it was designed to be, or the sensor reading the compartment has drifted, cold arrives faster than the drawer can use it and the back of the basket freezes first.

The compartment sweats inside. Is that the seal?

Often, though not always. Sweating means humid room air is reaching a cold surface. A tired gasket lets it in, and so does a door that no longer closes fully against a loaded basket. We watch how the door lands before assuming the gasket is the part that has to change.

Sub-Zero repair in Mandarin

Sub-Zero undercounter and refrigerator drawer repair

The small units in islands, bars and outdoor kitchens, where heat, tight clearance and a long run from the main cabinet make life hard.

An undercounter cabinet set into dark joinery with its base grille removed, the technician kneeling at floor level with a vacuum hose and a brush at the exposed coil. — Small cabinets, tight clearance, hard life

Small cabinets, hard lives

An undercounter refrigerator has to do the same job as a full-height cabinet with a fraction of the volume, a fraction of the coil and, usually, far less air to work with. The unit in a kitchen island has cabinetry on three sides. The one in a bar area often sits beside a wine unit, so each is breathing the other’s exhaust. The one on a covered lanai — and in Mandarin a great many houses have one — spends July drawing in air that is already close to blood temperature and saturated with moisture.

None of that is a fault. It is the operating condition, and it is why undercounter units and refrigerator drawers behave seasonally in a way that a full built-in in an air-conditioned kitchen does not. A unit that holds temperature perfectly from November through March and starts drifting in June is not necessarily failing. It may simply have lost the margin it needs, and the reason is usually airflow.

Clearance is the first thing we check

These cabinets vent through a grille, and that grille needs air in front of it and a path for the exhaust to leave. What we find, over and over, is a grille that has been boxed in by a later carpentry job: a toe-kick panel added during a remodel, a drawer front fitted flush where a gap was intended, a wine rack or a storage bin pushed up against the vent. Mandarin has a lot of houses on their second or third kitchen, and each round of joinery tends to tighten the tolerances around whatever appliance was already there.

Restore the clearance and a large proportion of warm-in-summer complaints go away without a part being fitted at all. That is a diagnosis we are happy to deliver, and it is one of the reasons the diagnostic is a flat fee rather than an hourly one.

When a drawer freezes what it should only chill

Refrigerator drawers are shallow, so the air inside them turns over quickly and a small error in control shows up fast. Produce with ice crystals on it, or drinks freezing overnight, usually means one of three things: the setting is lower than anyone remembers choosing, the sensor is reading warmer than the compartment really is, or the evaporator fan is running when it should have stopped. All three are ordinary diagnostics with a thermometer and a meter.

The reverse — a drawer that will not get cold — is more often a seal problem than a system problem. Drawer seals run on four sides and take a beating from being loaded, and a drawer that has been packed hard for years will have a seal that no longer springs back at the corners.

Sweating inside the compartment

An undercounter unit that is wet inside is being fed humid air. In this part of Duval County the dew point stays high for months, and a bar or lanai unit that is opened twenty times during an evening will take on a remarkable amount of moisture. If the sweating clears within a day of normal use, the appliance is doing its job. If it never clears, the seal, the drain or the defrost cycle is the place to look.

Noise

Small cabinets are close to people. An undercounter unit in a quiet den is audible at a level a full built-in across a kitchen never would be, so a compressor or fan that has become slightly rougher gets noticed early here. That is useful — early noise complaints on these units often catch a fan bearing before it takes anything else with it.

The visit

A flat $80 diagnostic, credited toward the repair. A written estimate before any part is ordered. Genuine OEM parts, 365 days on parts and 90 days on labour. Sealed-system work is performed under EPA Section 608 certification.

We service Sub-Zero refrigeration only. No other brand.

What it costs

What does Sub-Zero undercounter refrigeration repair cost in Mandarin?

Narrowed to the bands that fit this fault rather than the whole book, because quoting you the sealed-system ceiling for an ice maker would be no use to anybody.

Parts and labour for the repairs this page is about, plus the diagnostic that comes first.
What is being put right	Parts and labour
Diagnostic visit	$80 flat, credited toward the repair
Evaporator or condenser fan motor	$250–$550 parts and labour, after the diagnostic
Door gasket or seal replacement	$240–$620 parts and labour, after the diagnostic
Defrost heater, thermostat or sensor	$250–$640 parts and labour, after the diagnostic

Every line above is a range because the firm figure is written down after the diagnosis and not before it. The $80 covers coming out, testing the system and telling you what is wrong, and it comes off the repair the moment you say go ahead. The whole table, and what happens when a repair is not worth doing, is on the what it costs page.

The Condenser Is Above the Doors, Not Below The one piece of maintenance that reliably extends the life of a compressor, and the first thing we check on any cabinet that never stops running.
Condensation Along the Door Line A seal fails slowly and invisibly. Long before it lets go, it is letting in humid air, and the cabinet is paying for it in compressor hours.

Sub-Zero built-in refrigerator repair A cabinet running warm on one side, frost creeping across the freezer wall, or a unit that runs and runs without ever settling down.
Sub-Zero integrated column repair Panel-ready refrigerator and freezer columns that sit flush with the cabinetry until something moves, ices up or stops responding.
Sub-Zero wine storage repair Dual-zone units where the two compartments have stopped agreeing, humidity has drifted, or the fan has become audible from across the room.

$80 flat diagnostic, credited toward the repair. You get a written estimate before any part is ordered or any labour begins.

Questions we are asked

What owners ask about this repair

Why does my undercounter unit only struggle in summer?: Because it has less margin than a full-height cabinet and usually far less air. An island unit has cabinetry on three sides; a bar unit often breathes its neighbour's exhaust. In July the air it draws is hotter and wetter, so a unit that held its temperature in March has lost the headroom it was running on.
Why does a refrigerator drawer freeze what it should only chill?: A drawer is a small volume fed by a duct or damper sized for exactly that volume. When the airflow stops being metered the way it was designed to be, or the sensor reading the compartment has drifted, cold arrives faster than the drawer can use it and the back of the basket freezes first.
The compartment sweats inside. Is that the seal?: Often, though not always. Sweating means humid room air is reaching a cold surface. A tired gasket lets it in, and so does a door that no longer closes fully against a loaded basket. We watch how the door lands before assuming the gasket is the part that has to change.

Customer reviews

Owners who called about this

Chosen for this page because they describe the same fault, and printed in full.

4.64.6 out of 5 across all 64 reviews published on this site

5 out of 5
Our island unit sweats inside every August. He found the door was not closing fully against a loaded basket rather than a failed gasket, which cost me nothing but a better habit.
Leopold V.January 2026
4 out of 5
Our undercounter refrigerator was sweating around the door and the gasket had gone black at the base. He replaced the gasket, corrected the door alignment, and cleaned out the condensate tray completely.
Juniper L.November 2025
4 out of 5
He was straight with me that a small cabinet in a tight cupboard will always work harder in this climate, and that the fault was a worn fan rather than anything about the way it was fitted.
Honora G.January 2026

A wider selection, three-star entries first, is on the reviews page. All 64 are published across this site, beside the repair or the street each one came from.