A refrigerator that is not cooling almost always has a problem in one of three areas: airflow and the defrost system, the evaporator or condenser fans, or the sealed refrigeration system itself. On built-in and column units the control board manages defrost timing, so a warm compartment with a cold freezer often points to a defrost or airflow fault rather than a dead compressor.
What to Check First
A few quick checks are safe to try before booking a technician:
- Confirm the unit has power and the breaker has not tripped.
- Check that vents inside the compartment are not blocked by food.
- Make sure the condenser area is not clogged with dust.
- Listen for the compressor and fans running.
Protect Your Food
If the compartment is climbing above safe temperatures, move perishables to a working unit or a cooler with ice and keep the doors closed while you wait.
Likely Causes and Fixes
| Symptom | Likely Cause | What the Fix Involves |
|---|---|---|
Fresh food warm, freezer cold | Defrost heater or airflow fault | Test the defrost circuit and clear or repair airflow |
Whole unit warm | Failing compressor or sealed-system leak | Leak-test and repair the sealed system |
Runs constantly | Dirty condenser or bad fan | Clean the condenser; replace the fan motor |
Notes by Brand
The failure looks a little different across the brands we service. Here is what we check on each:
| Brand | What We Look At |
|---|---|
| Sub-Zero | Dual sealed systems and microprocessor defrost; we check airflow and the defrost circuit before the compressor. |
| Wolf | Not applicable to cooking units; refrigeration is handled on Sub-Zero and column models. |
| Bosch | Inverter compressors and evaporator fans; we verify the control and fan first. |
| Miele | MasterCool sensors and dampers; we test the NTC probes and airflow. |
| Viking | Built-in fan and defrost components accessed from the interior panel. |
| Liebherr | BioFresh and duo-cooling sensors; E0/E1 codes help narrow the fault. |
Have a Sub-Zero or Wolf That Needs Attention?
Book online and a brand-focused technician will diagnose it. Diagnostic and travel fees, if applicable, are confirmed before the appointment and before repair approval.
When to Call a Technician
If the compartment is still warming after the quick checks, or the compressor runs nonstop, book a technician. Sealed-system and defrost repairs require testing and appropriately qualified handling that are not DIY jobs.