The short answer
On the NPGCA 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 frosted evaporator leads, because the ice sheet is the single most common reason a working cabinet stops getting cold.
The observations that matter on the NPGCA line
- The freezer side is cold but the fresh-food side is not — On a cabinet that cools both compartments from one evaporator, this split is an airflow symptom, not a thermostat one.
- The compressor runs and never cycles off — Continuous running with a warm cabinet says the system is working and losing — either the heat is not leaving or the cold is not circulating.
- 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 NPGCA line
- Defrost has stalled and the evaporator has iced over, so no air moves — Ranked first on the NPGCA line: on any frost-free cabinet the evaporator is the part that fails softly — the ice builds over weeks, the owner notices warmth long before frost, and the unit keeps running the whole time. It is also the one cause whose signature you can confirm without a meter.
- 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.
- The condenser coil is blanketed in dust, or its fan has stopped — Heat has to leave the cabinet somewhere. A furred coil or a stopped condenser fan keeps the refrigerant hot on the high side, and the compartment warms even though everything is running.
- The door is not sealing — gasket, alignment or a shelf holding it open — At the bottom of the list, but never skip it: if everything above checks out, a seal that fails only under its own weight, or only when warm, is the classic answer to a fault that comes and goes.
What to check first, second and third
- First — look at the back wall of the freezer compartment for a sheet of ice — Empty the compartment and look at the vents.
- Then — listen at the freezer with the door switch held in — The evaporator fan should start within a few seconds.
- Only then — find the condenser coil and its fan, and look — Pull the cabinet out or take the base grille off.
- 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 NPGCA 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 NPGCA line
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
