The short answer
When the BBB family stops cooling while the compressor still runs, the fault is usually that cold air is not moving rather than that cold is not being made. This page ranks the causes for that build; the brand-generic article ranks them for the brand as a whole.
What you observe
- The unit never cycles off — A machine that cannot reach its target runs continuously and works its compressor far harder than normal.
- Cabinet warm while the unit is clearly running — Cold is being made somewhere and is not arriving, which is an airflow question.
- Cooling recovers for a day after the doors are left open — Near-diagnostic for a defrost fault: melting the ice restores the air path temporarily.
- The compartment is colder at the bottom than the top — An air-distribution problem rather than a failure to make cold.
- NEAR MISS - silent and not cold — That is a no-power or start-relay fault and belongs on a different page.
Causes, most likely first on BBB
- Evaporator or circulation fan not running — Ranked first on the BBB family: these cabinets rely on more than one fan, so one dead fan leaves part of the cabinet cold and part of it warm. What decides the order here is where the cold has to travel, and that is fixed for every model in the family. This moves above blocked airflow from a frosted evaporator, which leads the brand-generic order, because these models share one layout, so its weak point shows across the whole family.
- Blocked airflow from a frosted evaporator — Second: ice on the evaporator is not a side effect but the blockage itself: once the fins are bridged, the cabinet is sealed off from the only cold surface it has.
- Door seals, door alignment and loading — Third: a heavy built-in door can drop on its hinges and leave a gap at one corner that is invisible until tested.
- Condenser coil choked or its fan stalled — Fourth: a built-in cabinet vents through a narrow grille, so a blocked grille is as bad as a blocked coil.
- Sealed-system or compressor fault — Last: last, and on a built-in it usually means the cabinet comes out of its housing.
Check in this order, and why
- Listen at the cabinet for the circulation fan — It separates the two likeliest causes before any panel comes off.
- Check nothing is packed against the rear vents — Blocked vents give exactly the same symptom as a failed fan and cost nothing to rule out.
- Compare the two compartments against each other — One cold and one warm is an air path; both warm is the system or the condenser.
- Test each door seal with a sheet of paper — Last, because it explains a struggling cabinet rather than a warm one.
Before you open anything
Safety
Kill the power at the breaker first, shut the water at the stop tap before touching a fill line, and call at once if you see oil at the compressor or smell burning.
When to call a technician
Call once the fan runs, the coil is clean and the seals are good but the cabinet is still warm: what is left is the defrost circuit or the sealed system, and neither is owner work on this family.
Other BBB pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
