The short answer
On the HS line, a cabinet that hums but will not hold temperature is far more often an airflow or heat-rejection problem than a dead compressor — the machine is still working, it just cannot move the heat out. On this page the coil and the door seal lead, because between them they explain most cabinets that run continuously and still sit warm.
The observations that matter on the HS line
- Condensation or sweating on the inside walls — The cabinet is running above dew point for the room, which is the same fault seen from the humidity side.
- The cabinet is warm and the unit is plainly running — You can hear the compressor and feel warm air at the back, but the inside never comes down to temperature.
- NEAR MISS — the cabinet is silent and nothing is cold — That is a no-power, start-relay or control fault and it is a different page: it starts with the outlet and the cord, not with the airflow checks below.
What is usually behind this on the HS line
- The condenser coil is blanketed in dust, or its fan has stopped — Ranked first here because it is the cheapest fault to have and the cheapest to rule out: a coil that cannot shed heat makes a cabinet that runs constantly and cools poorly, and on the HS line the coil sits where household dust and pet hair reach it.
- The door is not sealing — gasket, alignment or a shelf holding it open — A door held fractionally open by an over-packed shelf, a tired gasket or a cabinet out of level loads the system permanently. It sits here because it is quick to clear, and clearing it stops you chasing a part that is fine.
- The evaporator fan has failed, seized or is being blocked — The evaporator fan is what pushes cold air into the compartments. When it stops, the coil still gets cold but the cabinet does not, which reads exactly like a cooling failure from the outside.
- Defrost has stalled and the evaporator has iced over, so no air moves — Last of the airflow causes here: the symptom is unmistakable once a panel is off — a solid slab of ice on the coil — so it is worth confirming only after the checks that need no dismantling.
What to check first, second and third
- First — find the condenser coil and its fan, and look — Pull the cabinet out or take the base grille off.
- Then — close the door on a sheet of paper and pull it out — Do it at the top, the middle and the bottom of each door.
- Only then — listen at the freezer with the door switch held in — The evaporator fan should start within a few seconds.
- STOP here if the next check needs a panel off or a meter on live terminals — Everything above can be done with nothing dismantled; past it the checks need test equipment.
Safety first
Safety
Unplug the appliance or switch off its breaker before any panel comes off — a capacitor can hold a charge after the power is off, and the compressor circuit is live whenever the cabinet is plugged in even when it is silent. Do not defrost a coil with a heat gun or a sharp tool: puncturing an evaporator tube turns a service call into a replacement.
When to call a technician
Call once the checks above are clean, or as soon as the evidence points inside the sealed system: refrigerant work is licensed work and the gauges to do it are not owner tools. On the HS line, call rather than continue if the coil has to come out to be cleared, if the fan needs the evaporator cover off, or if the cabinet trips the breaker when it starts. Call the same day if the freezer has been above 0 °F (−18 °C) or the fresh-food side above 40 °F (4 °C) for longer than a few hours, because at that point the food is the more expensive problem.
Other faults covered for the HS line
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
