The short answer for these models
The useful first question is not what has broken but where the cold is going. On a running unit it is being made and then lost, and the three places it is lost are the evaporator, the door and the condenser. Work through those before anyone mentions the compressor. Where this departs from the brand-level page is the ranking. A built-under cabinet has to shed its heat through one small grille, so anything that restricts that grille shows up as a fault long before it would on a freestanding unit, so on a BUFK unit the clearance and condenser checks lead.
How this shows up
- The BUFK form you own, which changes what the rest of this list means — Check whether the unit sits in a cut-out. If it does, its heat leaves through one grille, and that grille outranks everything inside the machine.
- The sides or the back of the cabinet are hot to the touch — The flanks or the rear are warm enough to notice, which means the heat being removed has nowhere to go.
- The door has to be pushed to shut, or it swings back open — A door held open by a shelf, a bottle or a tired hinge behaves exactly like a cooling fault.
Causes, most likely first on this family
- The thermostat, the sensor or the control — A control that thinks the cabinet is already cold stops asking for more, and a sensor sitting in the wrong airstream reports a temperature nobody has. The ranking moves here for a reason particular to these models: how the unit is built changes what this finding means. That is what puts the clearance and condenser checks ahead of everything else on the list.
- The sealed system or the compressor — Bottom of the list on purpose: it is the rarest of the five, the most expensive, and the only one that is not an owner check at any stage.
Check in this order, and why
- First — shut the door on a strip of paper and pull — Take a strip of paper round the whole frame rather than one corner of it. Seals fail locally, and one soft inch is enough to warm a cabinet. On these models this is the step the construction changes: what you found at the step above decides how much weight to give what you find here.
- Second — look at the cold source for frost — Empty enough of the compartment to see the rear wall or the cold plate. A carvable sheet of ice tells you the answer before any tool comes out.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Never chip frost off an evaporator with a knife, a screwdriver or a hot-air gun: the tubing behind it is thin aluminium, it punctures easily, and a punctured line turns a repairable fault into a scrapped cabinet. Leave the sealed system alone entirely — it is closed, pressurised and worked on under licence.
Where the owner job ends
Book the visit when the door seals, the vents, the condenser and the setting have all been checked and the cabinet still will not hold. Book it the same day if food is at risk, and say how long the unit runs between stops — a cabinet that never stops is a different fault from one that cycles normally and still runs warm.
The other symptoms covered for this family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
