Symptom · warm fresh-food, warm freezer, triage
A “not cooling” call from Corte Madera often starts with the display: a control board, thermistor or display alarm has flagged something, and the unit feels warmer than it should. The alarm is a clue, not a verdict — it reports what a sensor told it, and the useful work is figuring out whether the sensor, the airflow, or something larger is behind it.
The most common pattern is the fresh-food section warming while the freezer still holds. That split is diagnostic gold: it usually rules the compressor out and points at airflow, the evaporator fan, or a defrost fault. What a phone call can’t settle is which of those it is — the temperatures in each compartment, measured on-site, are what separate a fan job from a defrost job.
Quick answer
If both compartments are warm, start by checking power and the condenser; if only the fresh-food side is warm, suspect airflow, the evaporator fan or defrost — not the compressor. We triage with real temperature readings in each compartment before naming a part.
Diagnostic matrix, before any badges
This is the core of the page: match what your unit is doing to the likely cause, simplest first.
| What you see | Likely cause | On-site test | Typical repair |
|---|---|---|---|
| Fresh-food warm, freezer cold | Evaporator airflow / fan | Fan operation + evap temp | Evaporator fan, serial-matched |
| Fresh-food warm, frost on evap | Defrost circuit | Defrost heater + thermostat | Defrost component |
| Both compartments warming | Condenser airflow | Coil inspection + run time | Condenser clean / fan |
| Constant running, warm drift | Dirty condenser | Coil and fan check | Clean and re-verify |
| Warm + control alarm | Thermistor / board | Read code by serial | Sensor or board, verified |
| No cooling at all | Power / start / sealed | Electrical + gauge check | Diagnosed before condemning |
| Ice maker also slow | Shared airflow / freeze | Fill + temp check | Often water-side, not sealed |
Local proof & evidence
In Larkspur’s mix of older and remodeled kitchens, the same “warm fridge” complaint can be three different repairs one street apart, which is exactly why we measure instead of assume. A related tell: when the ice maker has also gone slow, jammed or is producing hollow cubes alongside the warming, it usually points to the water side rather than a deeper cooling failure. Across Belvedere and the bayfront we document every call the same way — temperature readings, condenser/evaporator photos, the model-tag image, and the OEM fan, gasket or control-board evidence once a part is confirmed.
Have the model number ready and tell us which compartments are warm. We’ll confirm whether the likely evaporator fan or defrost part is on the van before we book your window.
Mill Valley price ranges
Typical Mill Valley ranges for a Sub-Zero that is warm in the fresh-food section while the freezer still holds. The firm price comes after on-site diagnosis.
| Service / symptom | What is included | Price range | Time on site |
|---|---|---|---|
| Diagnostic visit | Model/serial read, fresh-food & freezer temps, airflow and condenser inspection | $165–$245 | 45–90 min |
| Condenser deep-clean & airflow restore | Coil clean, fan check, salt-dust and pet-hair removal | $190–$420 | 1–2 hr |
| Evaporator fan motor (OEM, serial-matched) | Diagnosis, OEM fan, post-repair temperature log | $385–$720 | 1–2 hr |
| Defrost heater / thermostat / sensor | Defrost-circuit test and component replacement | $340–$680 | 1–3 hr |
| Damper / air-baffle control | Airflow control test and damper replacement | $310–$620 | 1–2 hr |
| Sealed-system / compressor (after gauge proof) | EPA-compliant refrigerant diagnosis and repair | $1,500–$3,750 | 2–6 hr + parts |
What sets the final price: which component the readings confirm, the Sub-Zero line and part variant, cabinet access in panel-ready installs, and whether sealed-system testing is required.
Step by step
Before booking, these owner-safe checks tell us whether it is airflow, defrost or the sealed system — and what to have ready.
Fast facts
Mill Valley before-you-call checks
| Check | What to record | Why it matters |
|---|---|---|
| Doors and gaskets | Any frost line, condensation or gap | Humid air can mimic a cooling failure. |
| Temperature settings | Set point and displayed reading | Separates setting errors from actual drift. |
| Lower grille | Visible dust or blocked airflow | Condenser restriction is common in tight cabinets. |
| Recent power event | Outage, breaker trip or reset | Explains one-time alarms without replacing parts. |
| Compartment split | Fresh-food and freezer readings | Freezer holding usually lowers compressor suspicion. |
Do not force a pull-out, keep cycling power, or scrape away a repeated frost pattern before photos are taken. Those actions can hide the clue that separates a fan, defrost, gasket or sealed-system path.
For the stronger hub version of this page, use the Mill Valley temperature-log guide.
Reviews
“Our Sub-Zero 632 was warm up top — fresh-food climbed to 52°F while the freezer held at 0°F. Tech reached Homestead Valley within a few hours, found a failed evaporator fan and a dust-packed condenser, and brought it back to 37°F the same day. $415 for the fan and coil clean.”
— Hannah W., Homestead Valley 94941“Freezer fine, fridge side warming after the foggy week. They logged temps before touching anything and it was a defrost heater fault, not the compressor. $360, done in two hours in Strawberry.”
— Andre C., Strawberry 94941“650-series running constantly and drifting warm in Tam Valley. Salt air had corroded the condenser; a deep clean and airflow restore fixed it for $230 with no parts needed.”
— Owen B., Tam Valley 94941Not-cooling questions
That split usually points to the fresh-food evaporator airflow: a failing evaporator fan or a defrost fault, not the compressor. We confirm with compartment readings before replacing anything.
Check the freezer first — if it is holding, frozen food is safe for now. Move perishables from a warm fresh-food section to a cooler and call; most of these repairs are quick once diagnosed.
Not necessarily. The board reports what a sensor tells it. A faulty thermistor can trigger an alarm; we read the code against your serial before condemning a board.
Possibly, but it is far down the list for a warm-fresh-food-only complaint. We rule out airflow, fans, defrost and the condenser first, and verify the sealed system with gauges if needed.
Most warm-fresh-food repairs run $190–$720: a condenser/airflow restore at the low end, an OEM evaporator fan or defrost part at the high end. Sealed-system work, only after proof, runs $1,500–$3,750. Diagnosis is $165–$245, credited.
About 37°F in the fresh-food section and 0°F in the freezer. A fresh-food reading above 42°F with a still-cold freezer points to airflow, the evaporator fan or defrost — move perishables and book a window.
