--- title: "Refrigerator not cooling" description: "Sub-Zero refrigerator not cooling: a cabinet that runs warm, cools unevenly, or holds temperature overnight and not by day." url: "https://subzeromiami.support/symptoms/refrigerator-not-cooling/" date_modified: "2026-08-18" Appliance type: "Built-in refrigerators" --- # Sub-Zero refrigerator not cooling ### The fastest diagnosis is the code If the display is showing a code, read it first: it narrows this from five possible causes to one subsystem before anybody opens anything. A photograph of the display is the single most useful thing you can send us. ### What it usually turns out to be - **A condenser that cannot shed heat.** In South Florida this is the first suspect, and on units within a few blocks of the water it is the first suspect twice over — dust inland, salt corrosion on the coast. - **A fan out of range.** Condenser or evaporator; often logged as a fan code before anyone notices the temperature. - **A tired door gasket.** The cheapest cause on the list, and the one that imitates the most expensive. - **A defrost circuit that never finishes,** which shows as frost in one zone and warmth in another. - **The sealed system.** The expensive answer, and the one worth ruling the others out before reaching. ### When it stops being a five-minute check Frost on the evaporator, a compressor that runs without the cabinet coming down to temperature, or a unit that has been drifting for weeks is past the point where cleaning helps. Sealed system work starts around $1,200 here and is confirmed on site — but so is the far more common outcome, which is a condenser service in the low hundreds. The most common call What it usually means Warm on one side, fine on the other Holds overnight, drifts by day Compressor running far longer than it used to The fastest diagnosis is the code If the display is showing a code, read it first: it narrows this from five possible causes to one subsystem before anybody opens anything. A photograph of the display is the single most useful thing you can send us. What it usually turns out to be A condenser that cannot shed heat. In South Florida this is the first suspect, and on units within a few blocks of the water it is the first suspect twice over — dust inland, salt corrosion on the coast. A fan out of range. Condenser or evaporator; often logged as a fan code before anyone notices the temperature. A tired door gasket. The cheapest cause on the list, and the one that imitates the most expensive. A defrost circuit that never finishes, which shows as frost in one zone and warmth in another. The sealed system. The expensive answer, and the one worth ruling the others out before reaching. When it stops being a five-minute check Frost on the evaporator, a compressor that runs without the cabinet coming down to temperature, or a unit that has been drifting for weeks is past the point where cleaning helps. Sealed system work starts around $1,200 here and is confirmed on site — but so is the far more common outcome, which is a condenser service in the low hundreds. A door seal that has gone tired Close the door on a sheet of paper and pull: if it slides out easily anywhere, that part of the seal is not sealing. The cheapest cause on the list, and the one that imitates the most expensive. A condenser that cannot shed heat Pull the grille and look. Furred with dust inland, corroded within a few blocks of the water — in South Florida this is the first suspect, and on the coast it is the first suspect twice over. A fan running out of range Condenser or evaporator. It is often logged as a fan code before anybody notices the temperature, and it usually announces itself as a change in sound first. A defrost circuit that never finishes Frost in one zone and warmth in another is the pattern. On a dual-refrigeration cabinet, one side misbehaving while the other holds is the diagnosis in itself. The sealed system The expensive answer, and the one worth ruling the others out before reaching. A compressor that runs without the cabinet coming down to temperature is what points here. Pull the grille and look The condenser is behind it and no tools are needed. If it is furred with dust, that alone can be the whole problem — and it is the cheapest outcome on the page. Close the door on a sheet of paper Pull it out. If it slides easily anywhere around the frame, that part of the seal is not sealing. Check nothing is holding a door ajar either — a bottle on a shelf edge is a classic. Note whether it is one zone or all of it On a dual-refrigeration cabinet, one side warm while the other holds is not a detail — it is the diagnosis. Then book the visit Tell us which zone, and photograph the display if there is a code. The diagnostic comes off the bill when you go ahead with the work. --- **[Read full article: Refrigerator not cooling](https://subzeromiami.support/symptoms/refrigerator-not-cooling/)**