The short answer for these models
When the cabinet is warm but the machine is plainly running, the fault sits between the cold and the food, not in the compressor. That means airflow, the door, or heat the condenser cannot shed. Only after all three are clean is a sealed-system fault worth entertaining. 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 URBC unit the clearance and condenser checks lead.
What you observe
- The URBC form you own, which changes what the rest of this list means — See how much air the cabinet has. Boxed into cabinetry, and restriction explains more faults here than failure does.
- The cabinet is warm but you can hear it running — You can hear it working from the next room and the shelves are at room temperature, which is the exact combination this page is about.
- Frost has built into a sheet rather than a dusting — Frost thick enough to hold a fingerprint has stopped being condensation and started being the obstruction.
Causes, most likely first on this family
- The thermostat, the sensor or the control — Placed below the mechanical causes because a control fault is uncommon and because the checks above will have implicated it by elimination if it is the answer. This is where the order departs from the brand-level page: on the URBC models the construction settles it, so the clearance and condenser checks come before the checks that lead anywhere else.
- The sealed system or the compressor — Last, and deliberately so: it is the least common of the five and the only one that is not an owner job at any stage.
What to check first, and why that order
- First — shut the door on a strip of paper and pull — Do it at several points around the frame. Anywhere the paper slides out without resistance is a leak, and it takes a minute to find.
- Second — look at the cold source for frost — Judge the thickness, not the presence: a light dusting is normal, a slab is the fault. On these models this is the step the construction changes: the answer only tells you something once you know which form the unit is.
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. Nothing sharp and nothing hot goes near an evaporator: the tubing behind the ice is thin aluminium and a puncture ends the appliance rather than delaying it. The refrigerant circuit is sealed, pressurised and worked on under licence, so leave it entirely alone.
Where the owner job ends
Book the visit when the door, the frost and the condenser have all come back clean, because at that point the remaining candidates are a control or the sealed system. Move the food first and say on the phone whether the compressor runs continuously — that one answer tells the technician which half of the machine to bring parts for.
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.
