The short answer
A cabinet that runs continuously and still warms up has lost airflow far more often than it has lost refrigerant. The compressor is working; something is stopping the cold it makes from reaching the food. Listen at the freezer with the door open and the light switch held in. Hearing the evaporator fan separates an airflow fault from a fan fault before anything is opened. On a Smeg refrigerator the cause that ranks first is defrost cycle stalled, evaporator iced over.
What you observe
- The cabinet is warm but the compressor is clearly running — Cold is being made; it is not reaching the food.
- A solid sheet of frost on the freezer rear panel — The defrost system has stopped clearing the coil.
- NEAR MISS — the cabinet is silent and nothing is cold — That is a power or start-relay fault and it is a different page.
Causes, most likely first on a Smeg refrigerator
- Defrost cycle stalled, evaporator iced over — The heater or its control stops clearing the coil, frost builds into a solid sheet behind the freezer panel, and air stops moving while the compressor runs on. It ranks first on a Smeg refrigerator because the expensive parts are the last things to fail on this platform, which is exactly why the cheap causes are worked first.
- Condenser coil blanketed in dust — The coil rejects the heat the compressor removes, and once it is covered the machine runs continuously without ever getting the cabinet down. Second on this platform: a shallow plinth or a tight cut-out fouls a coil far faster than an open back does.
- Evaporator fan motor failed — The fan behind the freezer panel is what pushes cold into the fresh-food side, and when it stops the freezer stays cold while the refrigerator warms. Ranked here because a cold freezer beside a warm refrigerator is this fault and almost nothing else.
- Damper or air diffuser stuck — On a single-evaporator cabinet a flap meters cold air into the fresh-food side, and a stuck flap starves that side while the freezer stays fine. Ranked here because it mimics a failed fan exactly, so the fan has to be heard before this is considered.
- Door not sealing, or left ajar — Warm humid air entering continuously loads the evaporator with frost and the compressor with work, and the cabinet never recovers. Last, and the reason to work down the list rather than guess: a cabinet opened constantly, or one whose door is not pulled shut, never gets a chance to catch up.
Check in this order, and why
- Empty the freezer and look at the rear panel for a sheet of frost — A solid sheet rather than a dusting settles it immediately.
- Feel the coil area at the back or in the plinth for heat and dust — A thick dust blanket is visible and it is the cheapest fix here.
- Open the freezer, hold the door switch in and listen for the fan — A cold freezer with a warm cabinet is the fan's signature.
What an owner can safely check
- Empty the cabinet, switch it off and leave both doors open for a full defrost — Cold restored afterwards confirms the defrost system as the cause.
Tools: towelsAbout 45 min
- Unplug the cabinet and vacuum the condenser coil and its grille thoroughly — Do this twice a year on a compact or built-in cabinet, more with pets.
Tools: vacuum, soft brushAbout 25 min
- STOP at the point where the next check means live terminals or a panel removed — Everything past that line is a technician's work, however likely the cause above it looks.
Before you open anything
Safety
Unplug the cabinet or switch off its breaker before removing any interior panel — a capacitor can hold a charge after the power is off. Never cut, open or attempt to recharge a sealed refrigerant line.
When to call a technician
Call once the defrost, the coil, the door and the fan are all clean and the cabinet still runs warm: what is left is the sealed system, and refrigerant work is licensed work. On a European-controlled machine, ask what the control was reporting when it stopped — it usually records why it aborted, and that shortens the visit.
Nearest pages of this class
What this page does not cover
What this page covers is the refrigerator class as Smeg builds it, not an individual family or model line. If a page exists for your particular family or model, it is linked above and it is the better answer — go there first when your model is named. Left out on purpose: part numbers, connector colours, disassembly order and torque values, because every one of those varies by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
