The short answer
A BBBF cabinet that is warm but audibly running is giving you the most useful clue there is: something is made cold and it is not reaching the food. That changes both the ranking and the first check compared with the brand-generic page.
What you observe
- Freezer side still cold, fresh-food side warm — Near-diagnostic on a shared-evaporator cabinet, and it points at the air path rather than the system.
- 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.
- A sheet of frost on the evaporator or the rear wall — A stalled defrost: the ice itself is now blocking the air path.
- 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 BBBF
- Condenser coil choked or its fan stalled — Ranked first on the BBBF family: heat has to leave the cabinet somewhere, and a coil matted with dust or a stalled compartment fan means the machine runs without ever winning. These codes share an evaporator arrangement and a defrost scheme, so a finding on one is worth assuming on the rest. This moves above blocked airflow from a frosted evaporator, which leads the brand-generic order, because this family is a single build with fixed access points.
- Evaporator or circulation fan not running — Second: the fan is the one part in the cold side that turns continuously, and a cabinet that warms from the top down is usually telling you it has stopped.
- Blocked airflow from a frosted evaporator — Third: a tall built-in cabinet depends on forced air along its whole height, so an iced evaporator starves the far end of the cabinet first.
- Sealed-system or compressor fault — Fourth: last, and on a built-in it usually means the cabinet comes out of its housing.
- Door seals, door alignment and loading — Last: a heavy built-in door can drop on its hinges and leave a gap at one corner that is invisible until tested.
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.
- Look behind the rear panel for a frost sheet — A solid sheet rather than a light dusting confirms a defrost fault.
- 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.
- 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 BBBF pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
